Compilare: main.cpp: In function 'int main()': main.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare] 18 | for (int i = 2; i < M; i++) { | ~~^~~ main.cpp:22:23: warning: comparison of integer expressions of different signedness: 'int' and 'unsigned int' [-Wsign-compare] 22 | for (int i = 0; i < N; i++) { | ~~^~~ main.cpp:15:9: warning: unused variable 'u' [-Wunused-variable] 15 | int u[N]; | ^