func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 3e5 + 77;   long long a[N], f[N], l, r;   int n, k;   bool check(int mid) {     for (int i = 1; i <= n; i++) f[i] = 0;     f[0] = 1;     int pl = 1, pr;     for (int i = 1; i <= n; i++) {       while (a[i] - a[pl] > mid) pl++;       pr = i - k + 1;       for (int j = pl; j <= pr; j++) {         if (f[j - 1]) {           f[i] = 1;           break;         } else           pl++;       }     }     return f[n];   }   int main() {     scanf( %d%d , &n, &k);     for (int i = 1; i <= n; i++) {       scanf( %lld , &a[i]);       r = max(a[i], r);     }     for (int i = 1; i <= n; i++) f[i] = 0x3f3f3f3f;     sort(a + 1, a + 1 + n);     while (l <= r) {       int mid = (l + r) / 2;       if (check(mid))         r = mid - 1;       else         l = mid + 1;     }     printf( %lld , l);     return 0;   }   