标签:blog io os sp for div log ef amp
二分加贪心,水过了。贪心是因为,不能存在覆盖,当存在覆盖时,留小坐标的。
#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> #define N 300100 using namespace std; struct Point{ int left,right; }pl[N]; int query[N/3][2]; bool cmp(Point a,Point b){ if(a.right<b.right) return true; return false; } int find_index(int a,int n){ int l=0; int r=n-1; int ans=-1; while(l<=r){ int mid=(l+r)/2; if(pl[mid].right<=a){ ans=mid; l=mid+1; } else r=mid-1; } return ans; } int main(){ int n,m; while(scanf("%d%d",&n,&m)!=EOF){ for(int i=0;i<n;i++) scanf("%d%d",&pl[i].left,&pl[i].right); for(int i=1;i<=m;i++){ scanf("%d%d",&query[i][0],&query[i][1]); } sort(pl,pl+n,cmp); for(int i=1;i<=m;i++){ int a=query[i][0],b=query[i][1]; int bgn=find_index(a,n); int ans=0; int pos=a; for(int k=bgn+1;k<n;k++){ if(pl[k].right<=b){ if(pl[k].left>=pos){ ans++; pos=pl[k].right; } } else break; } printf("%d\n",ans); } } return 0; }
标签:blog io os sp for div log ef amp
原文地址:http://www.cnblogs.com/jie-dcai/p/4143747.html