Compilare: main.cpp: In function 'int main()': main.cpp:62:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i2 = 0; i2 < pos[i][j].size(); ++i2) { ~~~^~~~~~~~~~~~~~~~~~ main.cpp:70:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i2 = 0; i2 < pos[i][j].size(); ++i2) ~~~^~~~~~~~~~~~~~~~~~ main.cpp:61:15: warning: unused variable 'M' [-Wunused-variable] int M = 0, Min = 10000; ^ main.cpp:61:22: warning: unused variable 'Min' [-Wunused-variable] int M = 0, Min = 10000; ^~~