poj1456 Supermarket

原题: http://poj.org/problem?id=1456

解法1:stl+ priority_queue 很好的思路 79ms

#include<cstdio>#include<algorithm>#include<queue>using namespace std;struct W{int v;int d;}w[10010];bool operator <(W a,W b){return a.v<b.v;}int max(int a,int b){if(a>=b)return a;return b;}int cmp(W a,W b){return a.d>b.d;}int main(){int n;while(~scanf("%d",&n)){priority_queue<W>q1;int m=0;for(int i=0;i<n;i++){scanf("%d %d",&w[i].v,&w[i].d);m=max(w[i].d,m);}sort(w,w+n,cmp);int sum=0,pos=0;;for(int t=m;t>=1;t--) //枚举每一天{while(pos<n && w[pos].d==t){q1.push(w[pos]);pos++;}if(!q1.empty()){sum=sum+q1.top().v;q1.pop();}}printf("%d\n",sum);}return 0;} 

解法2: 157ms

#include<cstdio>#include<algorithm>using namespace std;struct W{int v;int d;}w[10010];int cmp(W a,W b)//先按时间排序小->大,留够时间给后面的商品卖 {if(a.v!=b.v){return a.v>b.v;//再按价值排序大->小,尽量在范围内卖出最大价值的商品 }else{return a.d<b.d;}}int max(int a,int b){if(a>=b)return a;return b;}int main(){int n;while(~scanf("%d",&n)){for(int i=0;i<n;i++){scanf("%d %d",&w[i].v,&w[i].d);}sort(w,w+n,cmp);int dp[10010]={0};int sum=0;for(int i=0;i<n;i++){int d=w[i].d;while(dp[d]!=0 && d>=1){d--;}if(d>=1){dp[d]=w[i].v;sum=sum+dp[d];}}printf("%d\n",sum);}return 0;}