Compilare: user.cpp: In function ‘int main()’: user.cpp:25:9: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation] if(x != y) ++nr; v[x] = y; ^~ user.cpp:25:26: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘if’ if(x != y) ++nr; v[x] = y; ^ user.cpp:5:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in", "r", stdin); ^ user.cpp:6:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out", "w", stdout); ^ user.cpp:10:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:19:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^