UESTC 电子科大专题训练 DP-N

题意：有n个人写m行代码，第i个人写一行代码会产生ai个bug，问bug小于b的方案数

思路：背包二维费用

AC代码：

#include "iostream"
#include "string.h"
#include "stack"
#include "queue"
#include "string"
#include "vector"
#include "set"
#include "map"
#include "algorithm"
#include "stdio.h"
#include "math.h"
#define ll long long
#define bug(x) cout<<x<<" "<<"UUUUU"<<endl;
#define mem(a) memset(a,0,sizeof(a))
#define mp(x,y) make_pair(x,y)
using namespace std;
const long long INF = 1e18+1LL;
const int inf = 1e9+1e8;
const int N=1e5+100;

ll n,m,b,mod,dp[505][505]={1};
int a[505];
int main(){
    ios::sync_with_stdio(false),cin.tie(0),cout.tie(0);
    cin>>n>>m>>b>>mod;
    for(int i=1; i<=n; ++i){
        cin>>a[i];
    }
    for(int i=1; i<=n; ++i)
        for(int k=1; k<=m; ++k){
            for(int j=a[i]; j<=b; ++j){
                dp[k][j]=dp[k-1][j-a[i]]+dp[k][j];
                dp[k][j]%=mod;
            }
    }
    ll ans=0;
    for(int i=0; i<=b; ++i){
        ans+=dp[m][i];
        ans%=mod;
    }
    cout<<(ans+mod)%mod<<endl;
    return 0;
}