滴滴笔试第一题30%AC,小弱求大神帮忙看下原因

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
int a[10][10];

struct pos{
    int x, y;
    int remain;
    pos(int px, int py, int premain) : x(px), y(py), remain(premain) {};
    int getx() {return x;}
    int gety() {return y;}
    int getcur()
    {
        return remain;
    }
};
void dfs(int x, int y, int n, int m, int pcur, vector<vector<pos> > &path, vector<pos> &temp)
{
    if(pcur < 0) {
        return ;
    }
    
    if(x == 0 && y == m - 1 && pcur >= 0) {
        path.push_back(temp);
        return ;
    }
    a[x][y] = 2;
    temp.push_back(pos(x, y, pcur));
    if(x + 1 < n && a[x + 1][y] == 1) {
        dfs(x + 1, y, n, m, pcur, path, temp);
    }
    if(y > 0 && a[x][y-1] == 1) {
        dfs(x, y - 1, n, m, pcur - 1, path, temp);
    }
    if(y + 1 < m && a[x][y+1] == 1) {
        dfs(x, y + 1, n, m, pcur - 1, path, temp);
    }
    if(x > 0 && a[x-1][y] == 1) {
        dfs(x - 1, y, n, m, pcur - 3, path, temp);
    }
    temp.pop_back();
    a[x][y] = 1;    
}
bool cmp(vector<pos> a, vector<pos> b)
{
    return a.back().getcur() < b.back().getcur();
}
void judge(vector<vector<pos> > &res)
{
    if(res.empty()) {
        cout << "Can not escape!" << endl;
        return ;
    }
    int n = res.size();
    sort(res.begin(), res.end(), cmp);
    vector<pos> pmin= res.front();
    for(int i = 0; i < pmin.size(); i++) {
        if(i == 0) {
            cout << "[" << pmin[i].getx() << "," << pmin[i].gety() << "]" ;
        }
        else {
            cout << "," << "[" << pmin[i].getx() << "," << pmin[i].gety() << "]" ;
        }
    }
    cout << endl;
}
int main()
{
    int n, m, P;
    cin >> n >> m >> P;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            scanf("%d", &a[i][j]);
        }
    }
    vector<vector<pos> > res;
    vector<pos> tmp;
    dfs(0, 0, n, m, P, res, tmp);
    judge(res);
    return 0;
    
}