Compilare: main.cpp: In function 'int main()': main.cpp:75:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if ( comp - 1 == mk.size() ) { ~~~~~~~~~^~~~~~~~~~~~ main.cpp:76:45: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf( fout, "1\n%d\n", mk.size() ); ^ main.cpp:77:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < mk.size(); i++ ) ~~^~~~~~~~~~~ main.cpp:100:45: warning: format '%d' expects argument of type 'int', but argument 3 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] fprintf( fout, "2\n%d\n", mk.size() ); ^ main.cpp:101:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0; i < mk.size(); i++ ) ~~^~~~~~~~~~~ main.cpp:27:34: 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:33:38: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf( fin, "%d%d", &a, &b ); ^