1#include <stdio.h>
2#include <stdlib.h>
3
4int compare(const void *a, const void *b) {
5    return (*(int*)a - *(int*)b);
6}
7
8int canPlaceBalls(int *position, int n, int m, int minDist) {
9    int count = 1, lastPosition = position[0];
10    for (int i = 1; i < n; i++) {
11        if (position[i] - lastPosition >= minDist) {
12            count++;
13            lastPosition = position[i];
14            if (count >= m)
15                return 1;
16        }
17    }
18    return 0;
19}
20
21int maxDistance(int* position, int n, int m) {
22    qsort(position, n, sizeof(int), compare);
23    int left = 1, right = position[n - 1] - position[0];
24    int answer = 0;
25    while (left <= right) {
26        int mid = (left + right) / 2;
27        if (canPlaceBalls(position, n, m, mid)) {
28            answer = mid;
29            left = mid + 1;
30        } else {
31            right = mid - 1;
32        }
33    }
34    return answer;
35}
36
37int main() {
38    int position[] = {1, 2, 3, 4, 7};
39    int n = 5;
40    int m = 3;
41    printf("%d\n", maxDistance(position, n, m));
42    return 0;
43}

1