poj 1976 A Mini Locomotive_简单dp

#include <iostream>
#include<cstdio>
#include<cstring>
using namespace std;
#define MAXN 50010
int dp[MAXN][4],num[MAXN],sum[MAXN];
int main(int argc, char** argv) {
	int t,n,i,j,k,m;
	scanf("%d",&t);
	while(t--){
		scanf("%d",&n);
		for(i=1;i<=n;i++)
			scanf("%d",&num[i]);
		scanf("%d",&m);
		sum[0]=0;
		for(i=1;i<=n;i++)
			sum[i]=sum[i-1]+num[i];
		memset(dp,0,sizeof(dp));
		for(i=1;i<=n;i++){
			for(j=1;j<=3;j++){
				k=i-m;
				if(k<0)
					k=0;
				dp[i][j]=max(dp[k][j-1]+sum[i]-sum[k],dp[i-1][j]);
			}
		}
		printf("%d\n",dp
[3]);
	}
	
	return 0;
}