1 /* 2 Name:NYOJ-626-intersection set 3 Copyright: 4 Author: 5 Date: 2018/4/12 21:30:10 6 Description: 7 二分查找水题 8 */ 9 #include <iostream> 10 #include <algorithm> 11 #include <set> 12 #include <cstdio> 13 using namespace std; 14 int nums1[50005], nums2[50005]; 15 int main() 16 { 17 ios::sync_with_stdio(false); 18 int m, n; 19 while (~scanf("%d %d", &m,&n)) { 20 int tmp; 21 for (int i=0; i<m; i++) { 22 scanf("%d", &nums1[i]); 23 } 24 for (int i=0; i<n; i++) { 25 scanf("%d", &nums2[i]); 26 } 27 sort(nums1, nums1+m); 28 sort(nums2, nums2+n); 29 int ct = 0; 30 for (int i=0; i<m; i++) { 31 if (binary_search(nums2, nums2+n, nums1[i]) == true) { 32 ct++; 33 } 34 } 35 printf("%d\n", ct); 36 } 37 return 0; 38 }