noip2004 FBI树

全为0的串为B串,全为1的串为I串，其余称为F串。

#include<string.h>#include<cstdio>#include<cstdlib>#include<vector>#include<iostream>using namespace std;const int NMAX=(1<<11)+1;struct node{char c;int value;int leftson,rightson;};int N,i,j;node tree[NMAX];char check(int left,int right){if(tree[left].c=='B'&&tree[right].c=='B')return 'B';else if(tree[left].c=='I'&&tree[right].c=='I')return 'I';else return 'F';}void LRD(int root){if(root!=-1){LRD(tree[root].leftson);LRD(tree[root].rightson);printf("%c",tree[root].c);}}int main(){scanf("%d",&N);for(i=(1<<N);i<(1<<(N+1));i++){scanf("%d",&tree[i].value);tree[i].leftson=-1;tree[i].rightson=-1;if(tree[i].value)tree[i].c='I';else tree[i].c='B';}int temp=N-1;while(temp>=0){for(i=1<<temp;i< 1<<(temp+1);i++){tree[i].leftson=2*i;tree[i].rightson=2*i+1;tree[i].c=check(2*i,2*i+1);}temp--;}LRD(1);printf("\n");return 0;}