Jump gameII

class Solution {
public:
    int jump(vector<int>& a) {
        int n=a.size();
        if(n<=1) return 0;
        int i=0, level=0, curmax=0, nextmax=0;
        while(i<=n-1){
            for(;i<=curmax && i<=n-1;i++){
                nextmax=max(nextmax, a[i]+i);
                if(nextmax>=n-1) return level+1;
            }
            curmax=nextmax;
            level++;
        }
        return -1;
    }
};

class Solution {
public:
    int jump(vector<int>& a) {
        int n=a.size();
        if(n<=1) return 0;
        int dp
;
        dp[0]=0;
        for(int i=1;i<n;i++){
            dp[i]=INT_MAX;
            for(int j=0;j<i;j++){
                if(a[j]>=i-j)dp[i]=min(dp[i], dp[j]+1);
            }
        }
        return dp[n-1];
    }
};