Codeforces 876 B Divisiblity of Differences

题目地址
题意：给你n个数，让你从中选出k个数来，使得k个数中任意两个数的差为m的倍数。问能不能选出来。
思路：把所有数对m取余，同样余数的数之间的差为m的倍数，所有我们只要判断有没有一个余数的数字数量大于k就好了。

#include <iostream>#include <cstring>#include <string>#include <queue>#include <vector>#include <map>#include <set>#include <stack>#include <cmath>#include <cstdio>#include <algorithm>#define N 100010#define LL __int64#define inf 0x3f3f3f3f 0#define lson l,mid,ans<<1#define rson mid+1,r,ans<<1|1#define getMid (l+r)>>1#define movel ans<<1#define mover ans<<1|1const int mod = 1000000007;using namespace std;int num;vector<int>flag[N];int main() {    cin.sync_with_stdio(false);    int n, m, k;    while (cin >> n >> k >> m) {        for (int i = 0; i < N; i++) {            flag[i].clear();        }        for (int i = 0; i < n; i++) {            cin >> num;            flag[num%m].push_back(num);            if (flag[num%m].size() == k) {                num %= m;                cout << "Yes" << endl;                for (int i = 0; i < k; i++) {                    cout << flag[num][i] << " ";                }                cout << endl;                return 0;            }        }        cout << "No" << endl;    }    return 0;}