二维dp为什么不对 QAQ

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int maxn=10086;
const int maxm=586;
int f[maxn][maxm],d[maxn],n,maxx,m;
int main(){
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++){
        scanf("%d",&d[i]);
    }
    for (int i=0;i<n;i++){
        for (int j=0;j<=m;j++){
            f[i+1][j+1]=f[i][j]+d[i+1];
            f[i+j][0]=f[i][j];
        }
    }
    for (int i=0;i<=m;i++){
        maxx=max(maxx,f[n-i-1][i]);
    }
    printf("%d",maxx);
    return 0;
}