func_code_string: #include <bits/stdc++.h>   const int MAXN = 1e6 + 5;   int n, m, k;   char str[21];   int x[MAXN], y[MAXN];   int s[MAXN], t[MAXN];   int p[21];   int f[(1 << 20) + 3], g[(1 << 20) + 3];   inline void presum() {     for (int i = 0; i <= k - 1; ++i) {       for (int S = 0; S <= (1 << k) - 1; ++S) {         if ((S >> i) & 1) continue;         f[S] = std::min(f[S ^ (1 << i)], f[S]);         g[S] = std::max(g[S ^ (1 << i)], g[S]);       }     }   }   int main() {     scanf( %d%d%d , &n, &m, &k);     scanf( %s , str);     for (int i = 0; i <= k - 1; ++i)       if (str[i] ==  1 ) s[0] |= (1 << i);     scanf( %s , str);     for (int i = 0; i <= k - 1; ++i)       if (str[i] ==  1 ) t[0] |= (1 << i);     for (int i = 1; i <= n; ++i) scanf( %d%d , x + i, y + i);     for (int i = 1; i <= k; ++i) p[i] = i;     for (int i = 1; i <= n; ++i) {       int p1 = -1, p2 = -1;       for (int j = 1; j <= k; ++j) {         if (p[j] == x[i]) p1 = j;         if (p[j] == y[i]) p2 = j;       }       std::swap(p[p1], p[p2]);       for (int j = 0; j <= k - 1; ++j)         if ((s[0] >> (p[j + 1] - 1)) & 1) s[i] |= 1 << j;       for (int j = 0; j <= k - 1; ++j)         if ((t[0] >> (p[j + 1] - 1)) & 1) t[i] |= 1 << j;     }     for (int i = 0; i <= (1 << k) - 1; ++i) f[i] = 1e9, g[i] = -1e9;     for (int i = 0; i <= n; ++i)       f[s[i]] = std::min(f[s[i]], i), g[t[i]] = std::max(g[t[i]], i);     presum();     int ans = -1e9, ansl = -1, ansr = -1;     for (int S = 0; S <= (1 << k) - 1; ++S) {       if (g[S] - f[S] >= m && __builtin_popcount(S) > ans) {         ans = __builtin_popcount(S);         ansl = f[S] + 1;         ansr = g[S];       }     }     ans = 2 * ans + k - __builtin_popcount(s[0]) - __builtin_popcount(t[0]);     printf( %d n%d %d n , ans, ansl, ansr);     return 0;   }   