Compilare: user.cpp: In function ‘int main()’: user.cpp:72:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("largestroot.in", "r", stdin); ^ user.cpp:73:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("largestroot.out", "w", stdout); ^ user.cpp:79:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(b, sizeof(char), l, stdin); ^ user.cpp: In function ‘void add(int*, int*, int*)’: user.cpp:46:25: warning: ‘t’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (t) e[++e[0]] = t; ^