Gemini Boy - ACM之路~

BZOJ 2752: [HAOI2012]高速公路(road) (线段树)

链接:http://www.lydsy.com/JudgeOnline/problem.php?id=2752

概率背景的题,不过稍微想想,稍微推一推,就能得到公式。然后注意到只要用线段树维护3个sum就行了,sum1 费用和, sum2 下标乘以费用的和 sum3下标的平方乘以费用的和

PS:。。。在写线段树的时候被一个傻逼问题bug住了好久,,调了好久。好吧 我就是煞笔

2版线段树的代码。

#include <cstdio>
#include <cstring>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

const int maxn = 100100;

long long sumo[maxn], sump[maxn];

struct SegNode {
	int left, right;
	long long sum1, sum2, sum3;
	long long add;

	int mid() {
		return (left + right) >> 1;
	}

	long long size() {
		return (right - left + 1);
	}
};

struct SegmentTree {

	SegNode tree[maxn*5];

	void pushUp(int idx) {
		tree[idx].sum1 = tree[idx<<1].sum1 + tree[idx<<1|1].sum1;
		tree[idx].sum2 = tree[idx<<1].sum2 + tree[idx<<1|1].sum2;
		tree[idx].sum3 = tree[idx<<1].sum3 + tree[idx<<1|1].sum3;
	}

	void pushDown(int idx) {
		if (tree[idx].add) {
			long long add = tree[idx].add;
			int right1 = tree[idx<<1].right;
			int left1 = tree[idx<<1].left;
			int right2 = tree[idx<<1|1].right;
			int left2 = tree[idx<<1|1].left;
			tree[idx].add = 0;
			tree[idx<<1].sum1 += tree[idx<<1].size() * add;
			tree[idx<<1|1].sum1 += tree[idx<<1|1].size() * add;
			tree[idx<<1].sum2 += (sumo[right1] - sumo[left1-1]) * add;
			tree[idx<<1|1].sum2 += (sumo[right2] - sumo[left2-1]) * add;
			tree[idx<<1].sum3 += (sump[right1] - sump[left1-1]) * add;
			tree[idx<<1|1].sum3 += (sump[right2] - sump[left2-1]) * add;
			tree[idx<<1].add += add;
			tree[idx<<1|1].add += add;
		}
	}

	void build(int left, int right, int idx) {
		tree[idx].left = left;
		tree[idx].right = right;
		tree[idx].sum1 = 0;
		tree[idx].sum2 = 0;
		tree[idx].sum3 = 0;
		tree[idx].add = 0;
		if (left == right)
			return ;
		int mid = tree[idx].mid();
		build(left, mid, idx<<1);
		build(mid+1, right, idx<<1|1);
	}

	void update(int left, int right, int idx, long long value) {
		if (tree[idx].left == left && tree[idx].right == right) {
			tree[idx].add += value;
			tree[idx].sum1 += tree[idx].size() * value;
			tree[idx].sum2 += (sumo[right] - sumo[left-1]) * value;
			tree[idx].sum3 += (sump[right] - sump[left-1]) * value;
			return ;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			update(left, right, idx<<1, value);
		else if (left > mid)
			update(left, right, idx<<1|1, value);
		else {
			update(left, mid, idx<<1, value);
			update(mid+1, right, idx<<1|1, value);
		}
		pushUp(idx);
	}

	long long query(int left, int right, int idx, int L, int R) {
		if (tree[idx].left == left && tree[idx].right == right) {
			//printf("%d %d %d\n", idx, left, right);
			return (R + L - 1) * tree[idx].sum2 - tree[idx].sum3 - 
				((long long)L * R - R) * tree[idx].sum1;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			return query(left, right, idx<<1, L, R);
		else if (left > mid)
			return query(left, right, idx<<1|1, L, R);
		else {
			return (query(left, mid, idx<<1, L, R) + query(mid+1, right, idx<<1|1, L, R));
		}
	}	
	
};
SegmentTree tree;

int N, M;

long long gcd(long long a, long long b) {
	return b ? gcd(b, a % b) : a;
}

void init() {
	memset(sumo, 0, sizeof(sumo));
	memset(sump, 0, sizeof(sump));
	for (int i = 1; i < maxn; i++)
		sumo[i] = sumo[i-1] + i;
	for (int i = 1; i < maxn; i++)
		sump[i] = sump[i-1] + (long long)i * i;
	scanf("%d %d", &N, &M);
	tree.build(1, N, 1);
}

void work() {
	char op[19];
	for (int i = 0; i < M; i++) {
		scanf("%s", op);
		if (op[0] == 'C') {
			int x, y;
			long long z;
			scanf("%d %d %lld", &x, &y, &z);
			tree.update(x, y-1, 1, z);
		} else {
			int x, y;
			scanf("%d %d", &x, &y);
			long long tmp = tree.query(x, y, 1, x, y);
			long long tem = (long long)(y - x + 1) * (y - x) / 2;
			long long ans = gcd(tmp, tem);
			printf("%lld/%lld\n", tmp / ans, tem / ans);
		}
	}
}

int main() {
	init();
	work();
	return 0;
}
#include <cstdio>
#include <cstring>
#include <string>
#include <iostream>
#include <algorithm>
using namespace std;

const int maxn = 100100;

long long sumo[maxn], sump[maxn];

struct SegNode {
	int left, right;
	long long sum1, sum2, sum3;
	long long add;
};

struct SegmentTree {

	SegNode tree[maxn*5];

	void pushUp(int idx) {
		tree[idx].sum1 = tree[idx<<1].sum1 + tree[idx<<1|1].sum1;
		tree[idx].sum2 = tree[idx<<1].sum2 + tree[idx<<1|1].sum2;
		tree[idx].sum3 = tree[idx<<1].sum3 + tree[idx<<1|1].sum3;
	}

	void pushDown(int idx, int left, int right) {
		if (tree[idx].add) {
			long long add = tree[idx].add;
			tree[idx].add = 0;
			tree[idx].sum1 += (right - left + 1) * add;
			tree[idx].sum2 += (sumo[right] - sumo[left-1]) * add;
			tree[idx].sum3 += (sump[right] - sump[left-1]) * add;
			if (left == right) return ;
			tree[idx<<1].add += add;
			tree[idx<<1|1].add += add;
		}
	}

	void update(int L, int R, int left, int right, int idx, long long value) {
		pushDown(idx, L, R);
		if (L >= left && R <= right) {
			tree[idx].add += value;
			return ;
		}
		int mid = (L + R) >> 1;
		if (left <= mid)
			update(L, mid, left, right, idx<<1, value);
		if (right >= mid+1)
			update(mid+1, R, left, right, idx<<1|1, value);
		pushDown(idx<<1, L, mid);
		pushDown(idx<<1|1, mid+1, R);
		pushUp(idx);
	}

	long long query(int L, int R, int left, int right, int idx) {
		pushDown(idx, L, R);
		if (L >= left && R <= right) {
			printf("%d %d %d\n", idx, left, right);
			return (right + left - 1) * tree[idx].sum2 - tree[idx].sum3 - 
				((long long)left * right - right) * tree[idx].sum1;
		}
		int mid = (L + R) >> 1;
		long long ans = 0;
		if (left <= mid)
			ans += query(L, mid, left, right, idx<<1);
		if (right >= mid + 1)
			ans += query(mid+1, R, left, right, idx<<1|1);
		return ans;
	}		
	
};
SegmentTree tree;

int N, M;

long long gcd(long long a, long long b) {
	return b ? gcd(b, a % b) : a;
}

void init() {
	memset(sumo, 0, sizeof(sumo));
	memset(sump, 0, sizeof(sump));
	for (int i = 1; i < maxn; i++)
		sumo[i] = sumo[i-1] + i;
	for (int i = 1; i < maxn; i++)
		sump[i] = sump[i-1] + (long long)i * i;
	scanf("%d %d", &N, &M);
}

void work() {
	char op[19];
	for (int i = 0; i < M; i++) {
		scanf("%s", op);
		if (op[0] == 'C') {
			int x, y;
			long long z;
			scanf("%d %d %lld", &x, &y, &z);
			tree.update(1, N, x, y-1, 1, z);
		} else {
			int x, y;
			scanf("%d %d", &x, &y);
			long long tmp = tree.query(1, N, x, y, 1);
			long long tem = (long long)(y - x + 1) * (y - x) / 2;
			long long ans = gcd(tmp, tem);
			printf("%lld/%lld\n\n", tmp / ans, tem / ans);
		}
	}
}

int main() {
	init();
	work();
	return 0;
}

BZOJ 1798: [Ahoi2009]Seq 维护序列seq

http://www.lydsy.com/JudgeOnline/problem.php?id=1798

题意很简单,就是维护区间和,然后区间加一个值,区间乘以一个值。

做法就是维护 a * x + b 这个统计量,别的就是普通的线段树~

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
using namespace std;

const int maxn = 101000;

long long value[maxn], mod;

struct SegNode {
	int left, right;
	long long sum, add, mul;

	int mid() {
		return (left + right) >> 1;
	}

	int size() {
		return right - left + 1;
	}
};

struct SegmentTree {

	SegNode tree[maxn*5];

	void pushUp(int idx) {
		tree[idx].sum = (tree[idx<<1].sum + tree[idx<<1|1].sum) % mod;
	}

	void pushDown(int idx) {
		tree[idx<<1].add = (tree[idx].mul % mod * tree[idx<<1].add % mod + tree[idx].add) % mod;
		tree[idx<<1|1].add = (tree[idx].mul % mod * tree[idx<<1|1].add % mod + tree[idx].add) % mod;
		tree[idx<<1].mul = tree[idx<<1].mul % mod * tree[idx].mul % mod;
		tree[idx<<1|1].mul = tree[idx<<1|1].mul % mod * tree[idx].mul % mod;
		tree[idx<<1].sum = (tree[idx<<1].sum % mod * tree[idx].mul % mod 
			+ tree[idx<<1].size() * tree[idx].add % mod) % mod;
		tree[idx<<1|1].sum = (tree[idx<<1|1].sum % mod * tree[idx].mul % mod 
			+ tree[idx<<1|1].size() * tree[idx].add % mod) % mod;
		tree[idx].add = 0;
		tree[idx].mul = 1;
	}

	void build(int left, int right, int idx) {
		tree[idx].left = left;
		tree[idx].right = right;
		tree[idx].sum = 0;
		tree[idx].mul = 1;
		tree[idx].add = 0;
		if (left == right) {
			tree[idx].sum = value[left] % mod;
			return ;
		}
		int mid = tree[idx].mid();
		build(left, mid, idx<<1);
		build(mid+1, right, idx<<1|1);
		pushUp(idx);
	}

	void update(int left, int right, int idx, int opt, long long val) {
		if (tree[idx].left == left && tree[idx].right == right) {
			if (opt == 1) {
				tree[idx].add = (tree[idx].add + val) % mod;
				tree[idx].sum = (tree[idx].sum + tree[idx].size() % mod * val) % mod;
			} else {
				tree[idx].add = tree[idx].add % mod * val % mod;
				tree[idx].mul = tree[idx].mul % mod * val % mod;
				tree[idx].sum = tree[idx].sum % mod * val % mod;
			}
			return ;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			update(left, right, idx<<1, opt, val);
		else if (left > mid)
			update(left, right, idx<<1|1, opt, val);
		else {
			update(left, mid, idx<<1, opt, val);
			update(mid+1, right, idx<<1|1, opt, val);
		}
		pushUp(idx);
	}

	long long query(int left, int right, int idx) {
		if (tree[idx].left == left && tree[idx].right == right) {
			return tree[idx].sum % mod;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			return query(left, right, idx<<1);
		else if (left > mid)
			return query(left, right, idx<<1|1);
		else {
			return (query(left, mid, idx<<1) % mod + query(mid+1, right, idx<<1|1));
		}
	}

};
SegmentTree tree;

int n, m;

void init() {
	scanf("%d %lld", &n, &mod);
	for (int i = 1; i <= n; i++)
		scanf("%lld", &value[i]);
	tree.build(1, n, 1);
}

void work() {
	scanf("%d", &m);
	for (int i = 1; i <= m; i++) {
		int opt, x, y;
		long long val;
		scanf("%d", &opt);
		if (opt != 3) {
			scanf("%d %d %lld", &x, &y, &val);
			tree.update(x, y, 1, 3-opt, val % mod);
		} else {
			scanf("%d %d", &x, &y);
			printf("%lld\n", tree.query(x, y, 1) % mod);
		}
	}
}

int main() {
	init();
	work();
}
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

const int maxn = 101000;

long long value[maxn], mod;

struct SegNode {
	int left, right;
	long long sum, add, mul;
};

struct SegmentTree {
	SegNode tree[maxn*5];

	void pushUp(int idx) {
		tree[idx].sum = tree[idx<<1].sum + tree[idx<<1|1].sum;
	}

	void pushDown(int idx, int left, int right) {
		long long add = tree[idx].add;
		long long mul = tree[idx].mul;
		tree[idx].sum = (tree[idx].sum % mod * tree[idx].mul % mod +
			(right - left + 1) * tree[idx].add % mod) % mod;
		tree[idx].add = 0;
		tree[idx].mul = 1;
		if (left == right) return ;
		tree[idx<<1].add = (mul % mod * tree[idx<<1].add % mod + add) % mod;
		tree[idx<<1|1].add = (mul % mod * tree[idx<<1|1].add % mod + add) % mod;
		tree[idx<<1].mul = tree[idx<<1].mul % mod * mul % mod;
		tree[idx<<1|1].mul = tree[idx<<1|1].mul % mod * mul % mod;
	}

	void build(int left, int right, int idx) {
		tree[idx].left = left;
		tree[idx].right = right;
		tree[idx].sum = 0;
		tree[idx].mul = 1;
		tree[idx].add = 0;
		if (left == right) {
			tree[idx].sum = value[left] % mod;
			return ;
		}
		int mid = (tree[idx].right + tree[idx].left) >> 1;
		build(left, mid, idx<<1);
		build(mid+1, right, idx<<1|1);
		pushUp(idx);
	}

	void update(int L, int R, int left, int right, int idx, int opt, long long value) {
		pushDown(idx, L, R);
		if (L >= left && R <= right) {
			if (opt == 1) {
				tree[idx].add = (tree[idx].add + value) % mod;
			} else {
				tree[idx].add = tree[idx].add % mod * value % mod;
				tree[idx].mul = tree[idx].mul % mod * value % mod;
			}
			return ;
		}
		int mid = (L + R) >> 1;
		if (left <= mid)
			update(L, mid, left, right, idx<<1, opt, value);
		if (right >= mid+1)
			update(mid+1, R, left, right, idx<<1|1, opt, value);
		pushDown(idx<<1, L, mid);
		pushDown(idx<<1|1, mid+1, R);
		pushUp(idx);
	}

	long long query(int L, int R, int left, int right, int idx) {
		pushDown(idx, L, R);
		if (L >= left && R <= right) {
			return tree[idx].sum % mod;
		}
		int mid = (L + R) >> 1;
		long long ans = 0;
		if (left <= mid)
			ans = (ans + query(L, mid, left, right, idx<<1)) % mod;
		if (right >= mid + 1)
			ans = (ans + query(mid+1, R, left, right, idx<<1|1)) % mod;
		return ans;
	}
};

SegmentTree tree;

int n, m;

void init() {
	scanf("%d %lld", &n, &mod);
	for (int i = 1; i <= n; i++) {
		scanf("%lld", &value[i]);
	}
	tree.build(1, n, 1);
}

void work() {
	scanf("%d", &m);
	for (int i = 1; i <= m; i++) {
		int opt, x, y;
		long long val;
		scanf("%d", &opt);
		if (opt != 3) {
			scanf("%d %d %lld", &x, &y, &val);
			tree.update(1, n, x, y, 1, 3-opt, val % mod);
		} else {
			scanf("%d %d", &x, &y);
			printf("%lld\n", tree.query(1, n, x, y, 1) % mod);
		}
	}
}

int main() {
	init();
	work();
}

HDU 4578:http://acm.hdu.edu.cn/showproblem.php?pid=4578

这里还有道加强版,维护区间1次方和,2次方和,3次方和,区间加一个数,乘一个数,赋值。

更新的做法类似,要注意特殊处理赋值操作,赋值操作相当于a=1,b=0。

然后对于查询,其实2次方和,3次方和都可以展开来搞~

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <iostream>
using namespace std;

const int maxn = 100100;
const int mod = 10007;

struct SegNode {
	int left, right;
	int sum1, sum2, sum3;
	int add, mul, set;

	int mid() {
		return (left + right) >> 1;
	}

	int size() {
		return right - left + 1;
	}
};

struct SegmentTree {

	SegNode tree[maxn*5];

	void pushUp(int idx) {
		tree[idx].sum1 = (tree[idx<<1].sum1 + tree[idx<<1|1].sum1) % mod;
		tree[idx].sum2 = (tree[idx<<1].sum2 + tree[idx<<1|1].sum2) % mod;
		tree[idx].sum3 = (tree[idx<<1].sum3 + tree[idx<<1|1].sum3) % mod;
	}

	void pushDown(int idx) {
		if (tree[idx].set != 0) {
			int set1 = tree[idx].set % mod;
			int set2 = set1 % mod * set1 % mod;
			int set3 = set2 % mod * set1 % mod;
			tree[idx<<1].set = set1;
			tree[idx<<1|1].set = set1;
			tree[idx<<1].add = 0;
			tree[idx<<1|1].add = 0;
			tree[idx<<1].mul = 1;
			tree[idx<<1|1].mul = 1;
			tree[idx<<1].sum1 = tree[idx<<1].size() * set1 % mod;
			tree[idx<<1|1].sum1 = tree[idx<<1|1].size() * set1 % mod;
			tree[idx<<1].sum2 = tree[idx<<1].size() * set2 % mod;
			tree[idx<<1|1].sum2 = tree[idx<<1|1].size() * set2 % mod;
			tree[idx<<1].sum3 = tree[idx<<1].size() * set3 % mod;
			tree[idx<<1|1].sum3 = tree[idx<<1|1].size() * set3 % mod;
			tree[idx].set = 0;
		} 
		int mul1 = tree[idx].mul % mod;
		int mul2 = mul1 % mod * mul1 % mod;
		int mul3 = mul2 % mod * mul1 % mod;
		int add1 = tree[idx].add % mod;
		int add2 = add1 % mod * add1 % mod;
		int add3 = add2 % mod * add1 % mod;
		tree[idx<<1].add = (tree[idx].mul % mod * tree[idx<<1].add % mod 
			+ tree[idx].add) % mod;
		tree[idx<<1|1].add = (tree[idx].mul % mod * tree[idx<<1|1].add % mod 
			+ tree[idx].add) % mod;
		tree[idx<<1].mul = tree[idx<<1].mul % mod * tree[idx].mul % mod;
		tree[idx<<1|1].mul = tree[idx<<1|1].mul % mod * tree[idx].mul % mod;
		int sum1 = tree[idx<<1].sum1;
		int sum2 = tree[idx<<1].sum2;
		int sum3 = tree[idx<<1].sum3;
		int size = tree[idx<<1].size();
		tree[idx<<1].sum1 = (sum1 % mod * mul1 % mod 
			+ size % mod * add1 % mod) % mod;
		tree[idx<<1].sum2 = (sum2 % mod * mul2 % mod 
			+ 2 * add1 % mod * mul1 % mod * sum1 % mod + size % mod * add2 % mod) % mod;
		tree[idx<<1].sum3 = (mul3%mod*sum3%mod + 3*mul2%mod*add1%mod*sum2%mod 
			+ 3*mul1%mod*add2%mod*sum1%mod + size%mod*add3%mod) % mod;
		sum1 = tree[idx<<1|1].sum1;
		sum2 = tree[idx<<1|1].sum2;
		sum3 = tree[idx<<1|1].sum3;
		size = tree[idx<<1|1].size();
		tree[idx<<1|1].sum1 = (sum1 % mod * mul1 % mod 
			+ size % mod * add1  % mod) % mod;
		tree[idx<<1|1].sum2 = (sum2 % mod * mul2 % mod 
			+ 2 * add1 % mod * mul1 % mod * sum1 % mod + size % mod * add2 % mod) % mod;
		tree[idx<<1|1].sum3 = (mul3%mod*sum3%mod + 3*mul2%mod*add1%mod*sum2%mod 
			+ 3*mul1%mod*add2%mod*sum1%mod + size%mod*add3%mod) % mod;
		tree[idx].add = 0;
		tree[idx].mul = 1;
	}

	void build(int left, int right, int idx) {
		tree[idx].left = left;
		tree[idx].right = right;
		tree[idx].sum1 = 0;
		tree[idx].sum2 = 0;
		tree[idx].sum3 = 0;
		tree[idx].set = 0;
		tree[idx].mul = 1;
		tree[idx].add = 0;
		if (left == right)
			return ;
		int mid = tree[idx].mid();
		build(left, mid, idx<<1);
		build(mid+1, right, idx<<1|1);
		pushUp(idx);
	}

	void update(int left, int right, int idx, int opt, int val) {
		if (tree[idx].left == left && tree[idx].right == right) {
			int val1 = val % mod;
			int val2 = val1 % mod * val1 % mod;
			int val3 = val2 % mod * val1 % mod;
			int sum1 = tree[idx].sum1;
			int sum2 = tree[idx].sum2;
			int sum3 = tree[idx].sum3;
			int size = tree[idx].size();
			if (opt == 1) {
				tree[idx].add = (tree[idx].add + val1 % mod) % mod;
				tree[idx].sum1 = (sum1 + size * val1 % mod) % mod;
				tree[idx].sum2 = (sum2 + 2 * sum1 % mod * val1 % mod 
					+ size % mod * val2 % mod) % mod;
				tree[idx].sum3 = (sum3 + 3 * sum2 % mod * val1 % mod 
					+ 3 * sum1 % mod * val2 % mod + size % mod * val3 % mod) % mod;
			} else if (opt == 2) {
				tree[idx].add = tree[idx].add * val1 % mod;
				tree[idx].mul = tree[idx].mul * val1 % mod;
				tree[idx].sum1 = sum1 % mod * val1 % mod;
				tree[idx].sum2 = sum2 % mod * val2 % mod;
				tree[idx].sum3 = sum3 % mod * val3 % mod;
			} else {
				tree[idx].add = 0;
				tree[idx].mul = 1;
				tree[idx].set = val1;
				tree[idx].sum1 = size % mod * val1 % mod;
				tree[idx].sum2 = size % mod * val2 % mod;
				tree[idx].sum3 = size % mod * val3 % mod;
			}
			return ;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			update(left, right, idx<<1, opt, val);
		else if (left > mid)
			update(left, right, idx<<1|1, opt, val);
		else {
			update(left, mid, idx<<1, opt, val);
			update(mid+1, right, idx<<1|1, opt, val);
		}
		pushUp(idx);
	}

	int query(int left, int right, int idx, int opt) {
		if (tree[idx].left == left && tree[idx].right == right) {
			if (opt == 1)
				return tree[idx].sum1;
			else if (opt == 2)
				return tree[idx].sum2;
			else
				return tree[idx].sum3;
		}
		pushDown(idx);
		int mid = tree[idx].mid();
		if (right <= mid)
			return query(left, right, idx<<1, opt);
		else if (left > mid)
			return query(left, right, idx<<1|1, opt);
		else {
			return (query(left, mid, idx<<1, opt) % mod + query(mid+1, right, idx<<1|1, opt)) % mod;
		}
	}
};

SegmentTree tree;

int N, M;

void work() {
	tree.build(1, N, 1);
	int x, y, val, opt;
	for (int i = 0; i < M; i++) {
		scanf("%d %d %d %d", &opt, &x, &y, &val);
		if (opt == 4)
			printf("%d\n", tree.query(x, y, 1, val));
		else
			tree.update(x, y, 1, opt, val);
	}
}

int main() {
	while (scanf("%d %d", &N, &M) != EOF) {
		if (N == 0 && M == 0) 
			break;
		work();
	}
}

线段树水题集锦

SPOJ GSS1 && SPOJ GSS3

链接:http://www.spoj.com/problems/GSS1/ http://www.spoj.com/problems/GSS3/

题意:GSS1和GSS3一样query都是区间最大连续和,只不过GSS3有个单点update罢了

做法:维护sum(区间和),maxSum(区间最大连续和),maxLeft(左儿子区间最大连续和),maxRight(右儿子区间最大连续和)

代码君:GSS1:http://ideone.com/5tepgk    GSS3:http://ideone.com/MsopAu

 

SPOJ FREQUENT

链接:http://www.spoj.com/problems/FREQUENT/

题意:给个不下降序列,无update,query是求区间重复出现最多的数

做法:注意到是不下降序列,那么这个问题就转化成求区间连续相同序列的长度,因为是不下降的,所以不用维护区间最左和最右的值,可以只维护maxLen,leftLen,rightLen。

代码君:http://ideone.com/nGIts7

 

SPOJ




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