Compilare: main.cpp: In function 'int main()': main.cpp:9:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("prefixe.in", "r", stdin); ^ main.cpp:10:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("prefixe.out", "w", stdout); ^ main.cpp:11:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int t; scanf("%d", &t); ^ main.cpp:13:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", str + 1); ^