점프 점프

#include <iostream>
#include <vector>
#define INF 987654321
#define MAXX 1001
using namespace std;
 
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
 
    int n;
    cin >> n;
    int map[MAXX] = {0};
    for (int i = 0; i < n; i++) {
        cin >> map[i];
    }
 
    int dp[MAXX] = {0}; //이전 단계에서 점프해서 도착했을 때 최소 횟수를 저장 
    for (int i = 0; i < n; i++) {
        dp[i] = INF;
    }
    dp[0] = 0;
 
    for (int i = 0; i < n; i++) {
        if (map[i] == 0) continue;
        
        for (int j = 1; j <= map[i]; j++) {
            if (i + j >= n) break;
            dp[i+j] = min(dp[i+j], dp[i]+1);
        }
    }
 
    // for (int i = 0; i < n; i++) cout << dp[i] << ' ';
    // cout << '\n';
 
    if (dp[n-1] == INF) cout << -1 << '\n';
    else
        cout << dp[n-1] << '\n';
    return 0;
}