Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ main.cpp:25:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:95:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < chain[i].size(); ++j){ ~~^~~~~~~~~~~~~~~~~ main.cpp:81:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.in", "r", stdin); ^ main.cpp:82:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.out", "w", stdout); ^ main.cpp:83:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:85:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ main.cpp:87:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ main.cpp:104:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &t, &x, &y); ^