Compilare: user.cpp: In function ‘int main()’: user.cpp:47:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:51:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:55:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:65:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:74:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:84:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:93:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^ user.cpp:102:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 0; i < r2; i++) ^