Compilare: main.cpp: In function 'int main()': main.cpp:25:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<=d; j++) ~^~~ main.cpp:28:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=1; i<=n; i++) ~^~~ main.cpp:31:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=2; i<=n; i++) ~^~~ main.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=1; j<=d; j++) ~^~~