求大佬指点！为啥这样ac不了？
链接：https://ac.nowcoder.com/acm/contest/72369/D
#include<bits/stdc++.h>
using namespace std;
#define N 3005
long long a[N],f[N][N];//dp数组，dp[i][j]表示前i个数中除以k的余数为j的当前最大和
int n,k;
int main(){
cin >> n >> k;
for(int i = 1; i <= n; i ++) {cin >> a[i];}
memset(f,-0x3f,sizeof f);
long long maxv = -0x3f3f3f3f;
f[0][0] = 0;
for(int i = 1; i <= n; i ++){
for(int j = 0; j < k; j ++){
f[i][j] = max(f[i - 1][(j - a[i] + k) % k] + a[i],f[i - 1][j]);
//能ac的状态方程： f[i][(j + a[i]) % k] = max(f[i - 1][j] + a[i],f[i - 1][(j + a[i]) % k]);
}
}
for(int i = 1; i <= n; i ++) maxv = max(maxv,f[i][0]);
if(maxv > 0)cout << maxv << endl;
else cout << -1 << endl;
return 0;
}
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