Compilare: main.cpp: In function 'int main()': main.cpp:99:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a = 0; a < nodes.size(); a++) { ~~^~~~~~~~~~~~~~ main.cpp:103:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int b = a + 1; b < nodes.size(); b++) { ~~^~~~~~~~~~~~~~ main.cpp:115:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a = 0; a < nodes.size(); a++) { ~~^~~~~~~~~~~~~~ main.cpp:36:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d %d " ,&type,&n); ^ main.cpp:39:29: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&k); ^ main.cpp:44:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d " ,&x); ^