HDOJ1024(m段子序列最大和模板题)

/*dalao详解：http://blog.csdn.net/jdplus/article/details/19974647 */

#include <iostream> 

#include <cstring>
#include <string>
#include <cstdio>
#include <algorithm>
#include <stack>
#include <math.h>
#include<iostream>

using namespace std;
#define INF  0xfffff;//0x代表十六进制

int maxsum(int *data, int m, int n)
{
int sum;
int *dp = (int*)calloc(n + 1, sizeof(int));  //前n项的最大值
int *pre = (int*)calloc(n + 1, sizeof(int)); //上一阶段最大值
for (int i = 1; i <= m; i++)  
{
sum = INT_MIN;
for (int j = i; j <= n; j++)
{
dp[j] = max(dp[j - 1], pre[j-1]) + data[j]; //前者是跟 后者另起头
pre[j - 1] = sum;
sum = max(sum, dp[j]);
}
}
free(dp);
free(pre);
return sum;
}

int main()
{
int m, n;
while (cin >> m >> n)
{
int*data=(int*)malloc(sizeof(int)*(n+1));
for (int i = 1; i <= n; i++) cin >> data[i];
cout << maxsum(data, m, n) << endl;
free(data);
}
return 0;
}