CodeForces-1213D Equalizing by Division
Description
You are given an array a consisting of n integers. In one move you can choose any aiai and divide it by 2 rounding down (in other words, in one move you can set \(a_i=\lfloor \frac{a_i}{2} \rfloor\)).
You can perform such an operation any (possibly, zero) number of times with any aiai.
Your task is to calculate the minimum possible number of operations required to obtain at least kk equal numbers in the array.
Don't forget that it is possible to have ai=0ai=0 after some operations, thus the answer always exists.
Input
The first line of the input contains two integers nn and kk (1≤k≤n≤2⋅1051≤k≤n≤2⋅105) — the number of elements in the array and the number of equal numbers required.
The second line of the input contains nn integers a1,a2,…,ana1,a2,…,an (1≤ai≤2⋅1051≤ai≤2⋅105), where aiai is the ii-th element of aa.
Output
Print one integer — the minimum possible number of operations required to obtain at least kk equal numbers in the array.
Examples
input
5 3
1 2 2 4 5
output
1
input
5 3
1 2 3 4 5
output
2
input
5 3
1 2 3 3 3
output
0
题解
直接暴力分解。
排序一遍之后统计每个数出现了多少次,出现k次的时候更新一遍答案即可,打div3的时候硬是没想到,基础过差
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 50;
int cnt[N];
int num[N];
int a[N];
int main() {
int n, k;
scanf("%d%d", &n, &k);
for (int i = 1; i <= n; i++) {
scanf("%d", &a[i]);
}
sort(a + 1, a + n + 1);
int res = 1e9;
for (int i = 1; i <= n; i++) {
int tmp = 0;
while (a[i]) {
cnt[a[i]]++;
num[a[i]] += tmp;
if (cnt[a[i]] == k) {
res = min(res, num[a[i]]);
}
tmp++; a[i] /= 2;
}
}
printf("%d\n", res);
return 0;
}