func_code_string: #include <bits/stdc++.h>   using namespace std;   int N, K;   int A[300005];   int DP[300005];   bool chk(int d) {     int mxp = 0;     for (int i = K; i <= N; i++) {       if (A[i] - A[DP[i - K] + 1] <= d) mxp = i;       DP[i] = mxp;     }     return mxp == N;   }   int main() {     cin >> N >> K;     for (int i = 1; i <= N; i++) cin >> A[i];     sort(A + 1, A + 1 + N);     int l = -1, r = 1e9;     while (l + 1 < r) {       int md = (l + r) / 2;       if (chk(md))         r = md;       else         l = md;     }     cout << r <<   n ;   }   