Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:14:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<g[x].size(); i++){ ~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:42:34: warning: unused variable ‘s2’ [-Wunused-variable] int n, i, j, k, a, b, ans, s1, s2; ^~ user.cpp:43:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:45:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &s[i]); ^ user.cpp:47:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d%d", &a, &b); ^