Compilare: user.cpp: In function ‘int main()’: user.cpp:203:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kthvalue.out", "w", stdout); ^ user.cpp:233:64: warning: ‘k’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d\n", query(left + x - 1, left + y - 1, k)); ^ user.cpp:137:50: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized] node = node->next[(w & (1 << lvl)) ? 1: 0]; ^ user.cpp:213:19: note: ‘x’ was declared here int type, x, y, k; ^ user.cpp:233:53: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%d\n", query(left + x - 1, left + y - 1, k)); ^