Compilare: main.cpp: In function 'int main()': main.cpp:45:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<m; i++) ~^~ main.cpp:47:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i; j<m; j++) ~^~ main.cpp:67:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<m; i++) ~^~ main.cpp:69:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i; j<m; j++) ~^~