Compilare: main.cpp: In function 'void heapify(int)': main.cpp:15:14: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] } else if(heap[node].second < max(heap[2 * node + 1].second, heap[2 * node + 2].second)) ^ main.cpp: In function 'void buildbst()': main.cpp:54:5: warning: this 'while' clause does not guard... [-Wmisleading-indentation] while(sum + (1 << i) <= n - 1) ^~~~~ main.cpp:55:31: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'while' sum += (1 << i++); i = 1; ^ main.cpp: In function 'int main()': main.cpp:105:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permsort2.in", "r", stdin); ^ main.cpp:106:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("permsort2.out", "w", stdout); ^ main.cpp:107:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:111:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] heap[n - x] = {i, x}; ^