hdu 1003,nefu 728 max sum

最新推荐文章于 2022-09-19 18:34:38 发布

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最新推荐文章于 2022-09-19 18:34:38 发布

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原文链接：http://www.cnblogs.com/nefu929831238/p/5440420.html

本文介绍了一种求解整数序列中具有最大和的连续子序列的算法，并提供了详细的实现代码。通过动态规划方法，文章阐述了如何高效地找到序列中的最大和及其起始与结束位置。

Description

Given a sequence a[1],a[2],a[3]......a[n], your job is to calculate the max sum of a sub-sequence. For example, given (6,-1,5,4,-7), 
the max sum in this sequence is 6 + (-1) + 5 + 4 = 14.

Input

The first line of the input contains an integer T(1<=T<=20) which means the number of test cases. Then T lines follow, each line starts with 
a number N(1<=N<=100000), then N integers followed(all the integers are between -1000 and 1000).

Output

For each test case, you should output two lines. The first line is "Case #:", # means the number of the test case. The second line contains
three integers, the Max Sum in the sequence, the start position of the sub-sequence, the end position of the sub-sequence. If there are more than one result, output the first one. Output a blank line between two cases.

Sample Input

2
5 6 -1 5 4 -7
7 0 6 -1 1 -6 7 -5

Sample Output

Case 1:
14 1 4

Case 2:
7 1 6


//前1个数的DP值>=0，就加；DP值<0,就重新开始，自己本身。

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>

using namespace std;
int data[100005],dp[100005];

int main()
{
    int c,num=0,n;
    cin>>c;
    while(c--)
    {
        num++;
        int maxx=-9999999,a=0,b=0;
        memset(dp,0,sizeof(dp));
        cin>>n;
        for(int i=0;i<n;i++)
        scanf("%d",&data[i]);
        dp[0]=data[0];
        for(int i=1;i<n;i++)
        {
            if(dp[i-1]>=0)
            {
                dp[i]=dp[i-1]+data[i];
            }
            else
            {
                dp[i]=data[i];
                a=i;
            }
            if(dp[i]>maxx)
            {
                maxx=dp[i];
                b=i;
            }
        }
        printf("Case %d:\n",num);
        printf("%d %d %d\n",maxx,a+1,b+1);
    }
    return 0;
}