一个完全背包 很裸,对于我这种DP渣渣都能1A。。
// by SiriusRen
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int cases,n,E,F,f[20050],w[505],v[505];
int main(){
scanf("%d",&cases);
while(cases--){
memset(f,0x3f,sizeof(f)),f[0]=0;
scanf("%d%d",&E,&F),E=F-E;
scanf("%d",&n);
for(int i=1;i<=n;i++)scanf("%d%d",&w[i],&v[i]);
if(E<0){puts("This is impossible.");continue;}
for(int i=0;i<=E;i++)
for(int j=1;j<=n;j++)
f[i+v[j]]=min(f[i+v[j]],f[i]+w[j]);
if(f[E]!=0x3f3f3f3f)printf("The minimum amount of money in the piggy-bank is %d.
",f[E]);
else puts("This is impossible.");
}
}