func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = 0x3f3f3f3f;   const long long INF = 2e18;   const int N = 1231234;   int n, m;   int a[N], b[N];   bool ok(long long x) {     int i, j;     for (i = 0, j = 0; i < m; ++i) {       while (j < n && abs(b[i] - a[j]) <= x) j++;     }     return j == n;   }   int main() {     while (cin >> n >> m) {       int i, j;       for (i = 0; i < n; ++i) scanf( %d , &a[i]);       for (i = 0; i < m; ++i) scanf( %d , &b[i]);       long long l = 0, r = INF;       while (l <= r) {         long long mid = (l + r) >> 1;         if (ok(mid))           r = mid - 1;         else           l = mid + 1;       }       printf( %I64d n , l);     }   }   