Compilare: main.cpp: In function 'void euler(int)': main.cpp:14:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < a[x].size(); i++ ) { ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:27:24: warning: unused variable 'cnt1' [-Wunused-variable] int n, m, i, x, y, cnt1 = 0; ^~~~