codeforces 828 D. High Load（思维，水题）

题目链接：http://codeforces.com/contest/828/problem/D

题解：任意去一个点为根然后有几个k就是几个子叶也就是根结点有几个分支然后最好的解法就是贪心，将剩下的点均匀的分到各个分支上就行具体看一下代码。

#include <iostream>

#include <cstring>

#include <cstdio>

using namespace std;

const int M = 2e5 + 10;

int main() {

    int n , k;

    scanf("%d%d" , &n , &k);

    int every = (n - k - 1) / k;

    int more = (n - k - 1) % k;

    int ad = 0;

    if(more == 0) ad = 0;

    else if(more == 1) ad = 1;

    else ad = 2;

    printf("%d\n" , every * 2 + 2 + ad);

    int cnt = 2 , pre = 1;

    for(int i = 1 ; i <= k ; i++) {

        pre = 1;

        for(int j = 1 ; j <= every + 1 ; j++) {

            cout << pre << ' ' << cnt << endl;

            pre = cnt++;

        }

        if(more) {

            more--;

            cout << pre << ' ' << cnt << endl;

            cnt++;

        }

    }

    return 0;

}