Compilare: user.cpp: In function ‘int main()’: user.cpp:63:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&t); ^ user.cpp:66:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&n,&m); ^ user.cpp:72:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&x,&y); ^ user.cpp:122:74: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(dfs1(comp[i][a], 2 * now) == sza && dfs1(comp[i][b], 2 * now + 1) == szb) { ^ user.cpp:122:38: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(dfs1(comp[i][a], 2 * now) == sza && dfs1(comp[i][b], 2 * now + 1) == szb) { ^