自己的usaco代码---PROB Mixing Milk

原创代码

仅供参考

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/*ID: 输你自己的PROG: milkLANG: C++*/#include <iostream>#include <cmath>#include <cstdlib>#include <cstring>#include <string> #include <algorithm>#include <cstdio>using namespace std;struct ss{int a,b;};ss s[5005];bool c(const ss &z,const ss &v){if(z.a!=v.a) return z.a<v.a;else return z.b>v.b;}int main(){freopen("milk.in","r",stdin);freopen("milk.out","w",stdout);memset(s,0,sizeof(s));int m,n;cin>>m>>n;for(int i=1;i<=n;i++)  cin>>s[i].a>>s[i].b;sort(s+1,s+1+n,c);int k=0;int ans=0;while(m!=0){int rep;k++;rep=min(s[k].b,m);ans+=s[k].a*rep;m-=rep;}cout<<ans<<endl;return 0;}

ps：这个问题是贪心，排序，每次选最便宜的，直到获得牛奶数达到