Compilare: main.cpp: In function 'void buildChain(int)': main.cpp:69:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0,it;i<g[node].size();++i){ ~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:33:47: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d %d", &task, &x, &y); ^ main.cpp: In function 'void read()': main.cpp:118:33: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &n, &q); ^ main.cpp:119:51: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] for(int i=1;i<=n;++i) fscanf(fin, "%d", &w[i]); ^ main.cpp:121:37: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d %d", &x, &y); ^