Compilare: user.cpp: In function ‘ll slv(int)’: user.cpp:45:5: warning: this ‘for’ clause does not guard... [-Wmisleading-indentation] for (int u: ch[at]) ^~~ user.cpp:52:2: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘for’ dp[at] *= inv[ch[at].size()]; dp[at] %= MOD; ^~ user.cpp: In function ‘int main()’: user.cpp:66:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("shuffle2.in", "r", stdin); ^ user.cpp:67:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("shuffle2.out", "w", stdout); ^ user.cpp:68:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:73:40: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] int a, b; scanf("%d%d", &a, &b); ^