45. Jump Game II

Posted 2020-07-28 积少成多

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.

Your goal is to reach the last index in the minimum number of jumps.

For example:
Given array A = [2,3,1,1,4]

The minimum number of jumps to reach the last index is 2. (Jump 1 step from index 0 to 1, then 3 steps to the last index.)

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题目：非负整数数组，假定一开始你在数组的第一个位置，数组中元素表示你能jump的最大距离。

你的目标是利用最少的步数  jump到数组末尾

返回最少的次数？

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思路：贪心的思路（什么是贪心，特征是什么？）

class Solution {
public:
    int jump(vector<int> nums){
        int result = 0;

        int last = 0;///the maximum distance that has been reached
        int curr = 0;///the maximum distance that can be reached by using "ret+1" steps

        for(int i = 0;i<nums.size();i++){
            if(i>last){
                result++;
                last = curr;
            }
            curr = max(curr,nums[i]+i);
        }
        return result;
    }
};