Compilare: main.cpp: In function 'int gcd(int, int)': main.cpp:8:13: warning: unused variable 'r' [-Wunused-variable] int r = b; ^ main.cpp:6:9: warning: unused variable 'r' [-Wunused-variable] int r = 0; ^ main.cpp: In function 'int main()': main.cpp:16:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.in", "r", stdin); ^ main.cpp:17:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.out", "w", stdout); ^ main.cpp:19:18: warning: 'a' is used uninitialized in this function [-Wuninitialized] cout << gcd(a, b); ^ main.cpp:19:18: warning: 'b' is used uninitialized in this function [-Wuninitialized]