class Solution {
public:
    int d[10001];
    int N;
    int go(vector<int>& nums,int now)
    {
        if(now>=N-1)
            return 0;
        if(d[now]!=0x7f7f7f7f) return d[now];
        d[now] = 0x7ffff;
        int now1 = 0x7ffff;
        for(int i = nums[now];i>=0;i--)
        {
            if(i+now>N)
                i = N-now;
            now1 = min(now1,go(nums,i+now)+1);
        }
        d[now] = now1;
        return d[now];
    }
    int jump(vector<int>& nums) {
        fill(d,d+10001,0x7f7f7f7f);
        N = nums.size();
        return go(nums,0);
    }
};

탑 다운 연습