CodeForces - 600B Queries about less or equal elements (二分查找 利用stl)
传送门:
http://codeforces.com/problemset/problem/600/B
Queries about less or equal elements
time limit per test
2 secondsmemory limit per test
256 megabytesinput
standard inputoutput
standard outputYou are given two arrays of integers a and b. For each element of the second array bj you should find the number of elements in array a that are less than or equal to the value bj.
Input
The first line contains two integers n, m (1 ≤ n, m ≤ 2·105) — the sizes of arrays a and b.
The second line contains n integers — the elements of array a ( - 109 ≤ ai ≤ 109).
The third line contains m integers — the elements of array b ( - 109 ≤ bj ≤ 109).
Output
Print m integers, separated by spaces: the j-th of which is equal to the number of such elements in array a that are less than or equal to the value bj.
Examples
Input
Copy
5 4
1 3 5 7 9
6 4 2 8
Output
Copy
3 2 1 4
Input
Copy
5 5
1 2 1 2 5
3 1 4 1 5
Output
Copy
4 2 4 2 5
分析:
题目意思:
输入数组A和B,要求输出数组A中比B[i]小的数的个数。
做法:
暴力会超时,利用二分查找
upper_bound(A, A+N, B[i])- A;返回大于B[i]按照正序应存放的地址,取地址后是下标。
code:
#include<bits/stdc++.h> using namespace std; typedef long long LL; #define max_v 200005 int a[max_v],b[max_v]; int main() { int n,m; while(cin>>n>>m) { for(int i=0;i<n;i++) cin>>a[i]; for(int i=0;i<m;i++) cin>>b[i]; sort(a,a+n); for(int i=0;i<m;i++) { if(i==m-1) { printf("%d\n",upper_bound(a,a+n,b[i])-a); }else { printf("%d ",upper_bound(a,a+n,b[i])-a); } } } return 0; }
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