Compilare: user.cpp: In function ‘int main()’: user.cpp:91:9: warning: unused variable ‘c’ [-Wunused-variable] int c = N + i; ^ user.cpp:85:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &M); ^ user.cpp:89:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^