P1087-FBI树

迈不过友情╰ 2023-06-01 08:50 7阅读 0赞

1 #include <bits/stdc++.h>
     2 #define _for(i,a,b) for(int i = (a);i < b;i ++)
     3 typedef long long ll;
     4 using namespace std;
     5 string S;
     6 int N;
     7 inline ll read()
     8 {
     9     ll ans = 0;
    10     char ch = getchar(), last = ' ';
    11     while(!isdigit(ch)) last = ch, ch = getchar();
    12     while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
    13     if(last == '-') ans = -ans;
    14     return ans;
    15 }
    16 inline void write(ll x)
    17 {
    18     if(x < 0) x = -x, putchar('-');
    19     if(x >= 10) write(x / 10);
    20     putchar(x % 10 + '0');
    21 }
    22 struct TreeNode
    23 {
    24     char val;
    25     TreeNode *left;
    26     TreeNode *right;
    27 };
    28 char judge(int le,int ri)
    29 {
    30     bool oflag = false;
    31     bool zflag = false;
    32     _for(i,le,ri+1)
    33     {
    34         if(S[i]=='0')
    35             zflag = true;
    36         else if(S[i]=='1')
    37             oflag = true;
    38     }
    39     if(zflag && !oflag)
    40         return 'B';
    41     else if(!zflag && oflag)
    42         return 'I';
    43     else
    44         return 'F';
    45     return -1;
    46 }
    47 TreeNode* build(int le,int ri)
    48 {
    49     TreeNode* tmp = (TreeNode*)malloc(sizeof(TreeNode));
    50     int mi = (le+ri)/2;
    51     tmp->val = judge(le,ri);
    52     if(le!=ri)
    53     {
    54         tmp->left = build(le,mi);
    55         tmp->right = build(mi+1,ri);
    56     }
    57     else
    58         tmp->left = tmp->right = NULL;
    59     return tmp;
    60 }
    61 void postorder(TreeNode *root)
    62 {
    63     if(!root)
    64         return ;
    65     postorder(root->left);
    66     postorder(root->right);
    67     printf("%c",root->val);
    68 }
    69 int main()
    70 {
    71     TreeNode* root;
    72     scanf("%d",&N);
    73     cin >> S;
    74     root = build(0,pow(2,N)-1);
    75     postorder(root);
    76     return 0;
    77 }

转载于:https://www.cnblogs.com/Asurudo/p/11286525.html