이분탐색으로 최대값을 구해주고 전체 파의 합에서 곱한 값을 빼주면 되는 문제
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
public class Main {
static int N;
static int K;
static long[] arr;
static boolean check(long mid) {
int cnt = 0;
for(int i = 0; i < N; i++) {
cnt += arr[i] / mid;
}
return cnt >= K;
}
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
StringTokenizer st = new StringTokenizer(br.readLine(), " ");
N = Integer.parseInt(st.nextToken());
K = Integer.parseInt(st.nextToken());
arr = new long[N];
long max = 0;
for(int i = 0; i < N; i++) {
arr[i] = Integer.parseInt(br.readLine());
max = Math.max(arr[i], max);
}
long left = 1;
long right = max;
long pa = 0;
while(left <= right) {
long mid = (left + right) / 2;
if(check(mid)){
left = mid + 1;
pa = mid;
} else {
right = mid - 1;
}
}
long result = 0;
for(int i = 0; i < N; i++) {
result += arr[i];
}
System.out.println(result - (pa * K));
}
}