Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:44:21: warning: unused variable 'val' [-Wunused-variable] int val = i.first; ^~~ main.cpp:45:21: warning: unused variable 'cntval' [-Wunused-variable] int cntval = i.second; ^~~~~~ main.cpp: In function 'int main()': main.cpp:70:26: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &N); ^ main.cpp:74:37: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &u, &v); ^ main.cpp:79:35: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &key[i]); ^ main.cpp: In function 'void dfs(int, int)': main.cpp:62:15: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized] ind[node] = ans; ~~~~~~~~~~^~~~~ main.cpp:18:9: warning: 'pos' may be used uninitialized in this function [-Wmaybe-uninitialized] int pos, mx = 0; ^~~