Compilare: main.cpp: In function 'int main()': main.cpp:134:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v[1].size() ; i++ ) a.insert ( { v[1][i].cost, { 1, v[1][i].x } } ); ~~^~~~~~~~~~~~~ main.cpp:147:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v[y.y].size() ; i++ ) if ( viz[v[y.y][i].x] == 0 ) a.insert ( { v[y.y][i].cost, { y.y, v[y.y][i].x } } ); ~~^~~~~~~~~~~~~~~