hdu 2159 FATE (二维完全背包)

#include <cstdio>
#include <map>
#include <iostream>
#include<cstring>
#include<bits/stdc++.h>
#define ll long long int
#define M 6
using namespace std;
inline ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
int moth[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int dir[4][2]={1,0 ,0,1 ,-1,0 ,0,-1};
int dirs[8][2]={1,0 ,0,1 ,-1,0 ,0,-1, -1,-1 ,-1,1 ,1,-1 ,1,1};
const int inf=0x3f3f3f3f;
const ll mod=1e9+7;
int n,m,k,s; //经验值,忍耐度,怪物类型,最大杀怪数 
int a[107]; //得到的经验值 
int b[107];    //消耗的忍耐度 
int dp[107][107]; //i忍耐度下杀j只怪得到的最高经验 
int main(){
    ios::sync_with_stdio(false);
    while(cin>>n>>m>>k>>s){
        memset(dp,0,sizeof(dp));
        for(int i=1;i<=k;i++)
            cin>>a[i]>>b[i];
        for(int i=1;i<=k;i++)
            for(int j=1;j<=s;j++){
                for(int kk=b[i];kk<=m;kk++){
                    dp[kk][j]=max(dp[kk][j],dp[kk-b[i]][j-1]+a[i]);
                }    
            }
        int ans=-1;
        for(int i=1;i<=m;i++){
            for(int j=1;j<=s;j++){
                if(dp[i][j]>=n){
                    ans=i;
                    break;
                }
            }
            if(ans==i) break;
        }
        if(ans==-1)
            cout<<ans<<endl;
        else cout<<m-ans<<endl;
    }
}