20210625 852 山脉数组的峰顶索引
题目链接：852. 山脉数组的峰顶索引 - 力扣（LeetCode） (leetcode-cn.com)
三分搜索
cpp
class Solution {
public:
int peakIndexInMountainArray(vector<int>& a) {
int l = 0;
int r = a.size()-1;
while(l<r) {
int m = l + (r-l) /2;
int ml = l + (m-l)/2 ;
int mr = r - (r-m) / 2;
// cout<<m<<" "<<l<<" "<<r<<" "<<ml<<" "<<mr<<endl;
if(a[ml]>=a[mr]) {
r = mr-1;
} else if(a[ml]<a[mr]) {
l = ml+1;
}
}
return l;
}
};
最后更新: 2022-11-15