链接:http://acm.nyist.net/JudgeOnline/problem.php?pid=86
用数组标记法爆内存,暴力搜索超时....有一种方法是 快排+二分查找.可以过,但是有点慢..
#include <iostream> #include <algorithm> #include <cstdio> using namespace std; int ball[1000005]; int main() { bool binsearch(int n,int key); int m,n; int tem; int i; scanf("%d%d",&m,&n); for (i=0;i<m;i++) scanf("%d",&ball[i]); sort(ball,ball+m); for (i=0;i<n;i++) { scanf("%d",&tem); if(binsearch(m,tem)) printf("YES\n"); else printf("NO\n"); } return 0; } bool binsearch(int n,int key) //在ball[]中查找key,数组长度为n { int low=0,high=n-1; int mid; while(low<=high) { mid=low+(high-low)/2; if(ball[mid]==key) return true; if(ball[mid]<key) low=mid+1; else high=mid-1; } return false; }
用set容器:
#include <iostream> #include <cstdio> #include <set> using namespace std; int main() { int n,m; int i,a; set<int>ss; scanf("%d%d",&n,&m); while(n--) { scanf("%d",&a); ss.insert(a); } for (i=0;i<m;i++) { scanf("%d",&a); if(ss.find(a)!=ss.end()) printf("YES\n"); else printf("NO\n"); } return 0; }
天下武功,唯快不破