之前我的题解感觉代码太长了，我改进一下

$AC$ $Code$

#include<bits/stdc++.h>
using namespace std;
int n,a[6],x;
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);cout.tie(0);
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>x;
        if(x>=90) a[5]++;
        else if(x>=80) a[4]++;
        else if(x>=70) a[3]++;
        else if(x>=60) a[2]++;
        else a[1]++;
    }
    cout<<a[1]<<endl<<a[2]<<endl<<a[3]<<endl<<a[4]<<endl<<a[5]<<endl;
}

#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n, a[1005], sum1 = 0, sum2 = 0, sum3 = 0, sum4 = 0, sum5 = 0;
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        if (a[i] >= 0 && a[i] <= 59)
        {
            sum1++;
        }
        if (a[i] >= 60 && a[i] <= 69)
        {
            sum2++;
        }
        if (a[i] >= 70 && a[i] <= 79)
        {
            sum3++;
        }
        if (a[i] >= 80 && a[i] <= 89)
        {
            sum4++;
        }
        if (a[i] >= 90 && a[i] <= 100)
        {
            sum5++;
        }
    }
    cout << sum1 << endl << sum2 << endl << sum3 << endl << sum4 << endl << sum5;
    return 0;
}

比上面的少一点代码，也差不多。

#include <iostream>
using namespace std;
int main()
{
    int n,a[1000],num1=0,num2=0,num3=0,num4=0,num5=0;
    cin >> n;
    for(int i=1;i<=n;i++)
    {
        cin >> a[i];
        if(a[i]<60)
        {
            num1++;
        }
        else if(a[i]<70)
        {
            num2++;
        }
        else if(a[i]<80)
        {
            num3++;
        }
        else if(a[i]<90)
        {
            num4++;
        }
        else
        {
            num5++;
        }
    }
    cout << num1 << endl << num2 << endl << num3 << endl << num4 << endl << num5;
}