Compilare: main.cpp: In function 'int main()': main.cpp:32:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ( arb.size() < n - 1 ) { ~~~~~~~~~~~^~~~~~~ main.cpp:40:46: warning: format '%d' expects argument of type 'int', but argument 4 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf( fout, "%d\n%d\n", s, arb.size() ); ^ main.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < arb.size(); i++ ) ~~^~~~~~~~~~~~ main.cpp:25:34: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d", &n, &m ); ^ main.cpp:27:65: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d%d", &mk[i].x, &mk[i].y, &mk[i].cost ); ^