已AC，放心食用

#include <iostream>
#include <algorithm>
using namespace std;
int n, x, speech[105], cnt;
int main()
{
    cin >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> x;
        if (!speech[x]++)
        {
            cnt++;
        }
    }
    cout << cnt << endl;
    for (int i = 1; i <= 100; i++)
    {
        if (speech[i] != 0)
        {
            cout << i << " " << speech[i] << endl;
        }
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int a[110];//用于a[1]~a[100]记录1~100出现的次数
int n, t, c = 0; 
int main()
{
	cin >> n;
	for(int i = 1; i <= n; i++){
		cin >> t;
		//t，出现过的数字
		a[t]++;
		//如果t是第一次出现
		if(a[t] == 1) c++; 
	}
	cout << c << endl;
	for(int i = 1; i <= 100; i++){
		if(a[i] > 0){
			cout << i << ' ' << a[i] << endl;
		}
	}
	return 0;
}