LeetCode周赛 + AcWing周赛（T4/T3）分析对比

AcWing 57 T3
Leetcode 双周赛80 T4

前言

两道题之间的共同点在于子数组价值的定义，LC为子数组的和乘上其长度，AcWing为子数组的和除上其长度（平均值）。

分析 - AcWing T3

#include 
#include 
#include 

using namespace std;

typedef long long LL;

const int N = 1000010;

int n;
LL s[N];
int stk[N];

int main()
{
    scanf("%d", &n);
    for(int i = 1; i <= n; i ++)
    {
        int x;
        scanf("%d", &x);
        s[i] = s[i - 1] + x - 100;
    }
    
    int top = 0,res = 0;
    stk[++ top] = 0;
    for(int i = 1; i <= n; i ++)
    {
        if(s[stk[top]] > s[i]) stk[++ top] = i;
        else if(s[stk[top]] < s[i])
        {
            int l = 0, r = top;
            while(l < r)
            {
                int mid = l + r >> 1;
                if(s[stk[mid]] < s[i]) r = mid;
                else l = mid + 1;
            }
            res = max(res, i - stk[r]);
        }
    }
    
    printf("%d\n", res);
    return 0;
}

分析 - LeetCode T4

class Solution {
public:

    typedef long long LL;

    long long countSubarrays(vector<int>& nums, long long k) {
        LL res = 0, sum = 0;
        for(int i = 0, j = 0; j < nums.size(); j ++)
        {
            sum += nums[j];
            while(sum * (j - i + 1) >= k) sum -= nums[i ++];
            res += j - i + 1;
        }
        return res;
    }
};