poj-2479 Maximum sum 【最大字串和】

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Description

Input

Output

Sample Input

1

10
1 -1 2 2 3 -3 4 -4 5 -5

Sample Output

13

Hint

Source

求两段的最大和，前后进行两次dp；

#include<stdio.h>
#include<iostream>
#include<math.h>
#include<stdlib.h>
#include<ctype.h>
#include<algorithm>
#include<vector>
#include<string>
#include<queue>
#include<stack>
#include<set>
#include<map>

using namespace std;

int t, n, p[100010], ans[100010];

int main()
{
	scanf("%d",&t);
	while (t--)
	{
		memset(ans,0,sizeof(ans));
		scanf("%d",&n);
		int b = 0, sum = -1000000000;
		for (int i = 0; i < n; i++)
		{
			scanf("%d", &p[i]);
			b += p[i];
			sum = max(b, sum);
			ans[i] = sum;
			if (b < 0) 
				b = 0;	
		}

		b = 0, sum = -1000000000;
		int tmp = -1000000000;

		for (int i = n - 1; i >= 1; i--)
		{
			b += p[i];
			sum = max(b, sum);
			tmp = max(tmp, ans[i - 1] + sum);
			if (b < 0) 
				b = 0;
		}
		printf("%d\n",tmp);
	}
	return 0;
}

poj-2479 Maximum sum 【最大字串和】

标签：

原文地址：http://blog.csdn.net/u014427196/article/details/44081955