Compilare: main.cpp: In function 'int solve(int)': main.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (o = 0; o < k[i].size(); o++) { ~~^~~~~~~~~~~~~ main.cpp:24:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (t = 0; t < v[j].size(); t++) { ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:46:12: warning: unused variable 'j' [-Wunused-variable] int i, j; ^