Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:15:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ main.cpp:23:19: 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:89:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < chain[i].size(); ++j) ~~^~~~~~~~~~~~~~~~~ main.cpp:75:37: 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:76:39: 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:77:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:79:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ main.cpp:82:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ main.cpp:98:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &t, &x, &y); ^