[Leetcode Solution] Jump Game II

Analysis 

• Let f[x] denote the minimum steps needed to jump to x.
• f[y]=min(f[x]+1) if x + A[x]>=y
• O(n) algorithm can be found.
• if the f[y]=f[x]+1 (x<y and x+A[x]>=y), then any position k ( x<k<y ) won't give f[y] a smaller value

Note

Code