• CF w1d1 B. Expansion coefficient of the array


    Let's call an array of non-negative integers a1,a2,…,an a k-extension for some non-negative integer k if for all possible pairs of indices 1≤i,j≤n the inequality k⋅|i−j|≤min(ai,aj) is satisfied. The expansion coefficient of the array a is the maximal integer k such that the array a is a k-extension. Any array is a 0-expansion, so the expansion coefficient always exists.

    You are given an array of non-negative integers a1,a2,…,an. Find its expansion coefficient.

    Input

    The first line contains one positive integer n — the number of elements in the array a (2≤n≤300000). The next line contains n non-negative integers a1,a2,…,an, separated by spaces (0≤ai≤109).

    Output

    Print one non-negative integer — expansion coefficient of the array a1,a2,…,an.

    Note

    In the first test, the expansion coefficient of the array [6,4,5,5] is equal to 1 because |i−j|≤min(ai,aj), because all elements of the array satisfy ai≥3. On the other hand, this array isn't a 2-extension, because 6=2⋅|1−4|≤min(a1,a4)=5 is false.

    In the second test, the expansion coefficient of the array [0,1,2] is equal to 0 because this array is not a 1-extension, but it is 0-extension.

    这么简单的一题想多了。。wa了3、4次,无语

    #include<iostream>
    using namespace std;
    int a[300005],minn,k=1e9+5;
    int main()
    {
    	int n;
    	cin>>n;
    	for(int i=1;i<=n;i++){
    		cin>>a[i];
    		int len=max(i-1,n-i);
    		if(k>a[i]/len)k=a[i]/len;
    	}
    	cout<<k;
    	return 0;
    }
    
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  • 原文地址:https://www.cnblogs.com/LiangYC1021/p/12656594.html
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