Compilare: main.cpp: In function 'void read()': main.cpp:24:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &K); ^ main.cpp:27:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &b); ^ main.cpp: In function 'int main()': main.cpp:53:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cezar.in", "r", stdin); ^ main.cpp:54:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cezar.out", "w", stdout); ^ main.cpp:78:9: warning: 'st' may be used uninitialized in this function [-Wmaybe-uninitialized] if(node != st){ ^~