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Jump Game

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Determine if you are able to reach the last index.

For example:
A = [2,3,1,1,4], return true.

A = [3,2,1,0,4], return false.

 

Analyse: suppose reachMe[i] represents whether you could reach i, then reachMe[i] should be calculated as:

for j from [0, i - 1], if could reach j, and nums[j] >= i - j, then reachMe[i] is true. 

 1 class Solution { 2 public: 3     bool canJump(vector<int>& nums) { 4         if (nums.size() < 2) return true; 5          6         vector<bool> reachMe(nums.size(), false); 7         reachMe[0] = nums[0] ? true : false; 8          9         for (int i = 1; i < nums.size(); i++) {10             for (int j = i - 1; j >= 0; j--) {11                 if (reachMe[j] && nums[j] >= i - j) {12                     reachMe[i] = true;13                     break;14                 }15             }16         }17         return reachMe[nums.size() - 1];18     }19 };

 

Jump Game