Compilare: main.cpp: In function 'int main()': main.cpp:42:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v[x].size() ; i++ ) if ( r[x] + v[x][i].cost < r[v[x][i].dest] ) r[v[x][i].dest] = r[x] + v[x][i].cost, M.insert ( { r[v[x][i].dest], v[x][i].dest } ); ~~^~~~~~~~~~~~~