1102. Invert a Binary Tree (25)

Posted 2020-10-01

#include<iostream>
#include<string>
#include<map>
#include<vector>
#include<algorithm>
#include<queue>
#include<set>
#include<stack>
using namespace std;

struct node {
    int data;
    int left=-1, right=-1;
};

node arr[11];
int num;    


void posti(int root) {

    if (arr[root].left != -1) {
        posti(arr[root].left);
    }

    if (arr[root].right != -1) {
        posti(arr[root].right);
    }

    swap(arr[root].left, arr[root].right);

}

bool f = 0;

void bfs(int root) {

    queue<int> q;
    q.push(root);

    while (!q.empty()) {
        int temp = q.front();
        q.pop();
        if (f == 0) {
            f = 1;
            cout << temp;
        }
            
        else
            cout << ‘ ‘ << temp;
        if (arr[temp].left != -1)q.push(arr[temp].left);
        if (arr[temp].right != -1)q.push(arr[temp].right);
    }

}
bool k = 0;

void inorder(int root) {
    //cout << arr[root].left;
    if (arr[root].left != -1) {
        inorder(arr[root].left);
    }

    if (k == 0) {
        cout << root;
        k = 1;
    }

    else
        cout << ‘ ‘ << root;

    if (arr[root].right != -1) {
        inorder(arr[root].right);
    }
}

int main() {
    
    int isroot[11];
    cin >> num;
    fill(isroot, isroot + 11, 0);
    for (int i = 0; i < num; i++) {
        string s1, s2;
        cin >> s1 >> s2;
        arr[i].data = i;
        if (s1 != "-"){
            arr[i].left = stoi(s1);
            isroot[stoi(s1)] = 1;
        }

        if (s2 != "-"){
            arr[i].right = stoi(s2);
            isroot[stoi(s2)] = 1;
        }
    }

    int r = 0;
    for (int i = 0; i < num; i++) {
        //cout << isroot[i];
        if (isroot[i] == 0) {
            
            r = i;
            break;
        }
    }
    //cout << r;
    posti(r);

    bfs(r);
    cout << endl;
    inorder(r);
    system("pause");
    
}