Compilare: user.cpp: In function ‘void read()’: user.cpp:40:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1; j<=a.length(); j++) ^ user.cpp:34:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v); ^ user.cpp:35:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:36:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &m); ^ user.cpp: In function ‘int main()’: user.cpp:174:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ferma3.in", "r", stdin); ^ user.cpp:175:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ferma3.out", "w", stdout); ^ user.cpp: In function ‘void part2()’: user.cpp:168:48: warning: ‘mem_c’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d %d\n%c", mem_i-1, mem_j-1, mem_c); ^