45. Jump Game II

转载于 2018-04-06 20:36:39 发布 · 77 阅读

本文介绍了一种算法，用于解决给定非负整数数组中从起始位置到末尾位置所需的最少跳跃次数的问题。该算法通过遍历数组并记录最远可达位置来确定最少跳跃次数。

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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.)

Note:
You can assume that you can always reach the last index.

class Solution {
public:
    int jump(vector<int>& nums) {
        if(nums.size()<2)
        {
            return 0;
        }
        int current_max_index = nums[0];
        int pre_max_max_index = nums[0];
        int jump_min = 1;
        for(int i=1; i<nums.size(); i++)
        {
            if(i>current_max_index)
            {
                jump_min++;
                current_max_index = pre_max_max_index;
            }
            if(pre_max_max_index<nums[i]+i)
            {
                pre_max_max_index = nums[i] + i;
            }
        }
        return jump_min;
            
    }
};