Compilare: main.cpp: In function 'int main()': main.cpp:38:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ord.len; i++){ ^ main.cpp:48:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < a[i].len; j++) ^ main.cpp:57:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < a[i].len; j++) ^