Jump Game

class Solution {
public:
    bool canJump(int A[], int n) {
        if (n < 2) return true;
        int cpos = A[0];
        for (int i = 0; i <= cpos; ++i) {
            int cval = i + A[i];
            if (cval >= n - 1) return true;
            if (cval > cpos) cpos = cval;
        }
        
        return false;
    }
};