Compilare: user.cpp: In function ‘int main()’: user.cpp:14:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.in", "r", stdin); ^ user.cpp:15:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.out", "w", stdout); ^ user.cpp:17:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:22:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v1, &v2); ^ user.cpp:106:19: warning: ‘next’ may be used uninitialized in this function [-Wmaybe-uninitialized] linie[c]=v; ^ user.cpp:69:19: warning: ‘next’ may be used uninitialized in this function [-Wmaybe-uninitialized] linie[c]=v; ^