1110. Complete Binary Tree (25)

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

struct node {
    int left=-1, right=-1;
    int val;
};
int num;
int cnt[10001];
node arr[21];
int c = 0;
int last;
bool f;
void bfs(int root) {

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

    while (!q.empty()) {
        int temp = q.front();
        

        if (temp == -1) {
            //cout << c;
            if (c == num) {
                f = 1;
            }

            else
                f = 0; 
            break;


        }

        q.pop();
        c++;
        q.push(arr[temp].left);
        q.push(arr[temp].right);
        last = temp;

    }

}




int main() {
    
    
    cin >> num;
    

    for (int i = 0; i < num; i++) {
        arr[i].val = i;
        string l, r;
        cin >> l >> r;
        if (l != "-") {
            arr[i].left = stoi(l);
            cnt[stoi(l)] = 1;
        }
            
        if (r != "-") {
            arr[i].right = stoi(r);
            cnt[stoi(r)] = 1;
        }
            
    }

    int root = 0;
    while (cnt[root] == 1) {
        root++;
    }
    
    bfs(root);
    //cout << f;

    if (f == 1) {
        cout << "YES" << ' ' << last;
    }

    else {
        cout << "NO" << ' ' << root;
    }
    system("pause");
    
}

一开始没考虑到有可能会大于10的数字，用了char，导致一直过不了三个点。。。