Compilare: main.cpp: In function 'int main()': main.cpp:12:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv.in", "r", stdin); ^ main.cpp:13:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("secv.out", "w", stdout); ^ main.cpp:15:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^ main.cpp:17:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ main.cpp:26:9: warning: 'line1' may be used uninitialized in this function [-Wmaybe-uninitialized] int line1, line2; ^~~~~