没函数题解

#include <bits/stdc++.h>
using namespace std;
int a[205];
bool vis[205];
struct Node {
    int x;
    int step;
};
int main() {
    int n, s, e;
    cin >> n >> s >> e;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    queue <Node>q;
    q.push({s, 0});
    vis[s] = true;
    int ans = -1;
    while(!q.empty()) {
        Node fr = q.front();
        q.pop();
        if(fr.x == e) {
            ans = fr.step;
            break;
        }
        int it = fr.x + a[fr.x];
        if(it <= n && !vis[it]) {
            vis[it] = true;
            q.push({it, fr.step + 1});
        }
        it = fr.x - a[fr.x];
        if(it <= n && !vis[it]) {
            vis[it] = true;
            q.push({it, fr.step + 1});
        }
    }
    cout << ans;
}