了解一下快速读入的代码

inline int readint()
{
    char c = getchar();
    while(!isdigit(c)) c=getchar();
    int x=0;
    while(isdigit(c))
    {
        x=x*10+c-'0';
        c=getchar();
    }
    return x;
}

快速输出

int buf[10];
inline void writeint(int i)
{
    int p =0;
    if(i==0)p++;
    else while(i)
    {
        buf[p++]=i%10;
        i/=10;
    }
    for(int j=p-1;j>=0;j--)putchar('0'+buf[j]);
}

#include <bits/stdc++.h>
#define cl(a) memset(a,0,sizeof(a))
#define sc(x) scanf("%d",&x)
#define pf(x) printf("%d\n",x)
#define rep(i,a,b) for(int i=a;i<=b;i++)
#define per(i,a,b) for(int i=a;i>=b;i--)
#define fi first
#define se second
using namespace std;
const int mod=1e9+7;
typedef long long ll;
const int maxn=2e6+50;
const int inf=0x3f3f3f3f;
typedef pair <int,int> PII;
ll fpow(ll n,ll k,ll p =mod){ll r=1;for(;k;k>>=1){if(k&1)r=r*n%p;n=n*n%p;}return r;}
ll inv(ll n, ll p=mod) {return fpow(n,p-2,p);}
ll fact[maxn];
void init(){fact[0]=1;for(int i=1;i<maxn;i++)fact[i]=fact[i-1]*i%mod;}
ll C(ll n,ll m,ll p){ll r = fact[n]; r = r * inv(fact[m])%p; r = r*inv(fact[n-m])%p;return r;}
inline int readint()
{
    char c = getchar();
    while(!isdigit(c)) c=getchar();
    int x=0;
    while(isdigit(c))
    {
        //cout<<c<<endl;
        x=x*10+c-'0';
        //cout<<x<<endl;
        c=getchar();
    }
    //cout<<x<<endl;
    return x;
}
int buf[10];
inline void writeint(int i)
{
    int p =0;
    if(i==0)p++;
    else while(i)
    {
        buf[p++]=i%10;
        i/=10;
    }
    for(int j=p-1;j>=0;j--)putchar('0'+buf[j]);
}
int cnt[200];
int a[maxn];
int main()
{
    int n;

    while(n=readint())
    {
       // cout<<n<<endl;
        cl(cnt);
        int f=0;
        rep(i,1,n) {int x=readint();cnt[x]++;}
        rep(i,1,100)
        {
            rep(j,1,cnt[i])
            if(!f) writeint(i),f=1;
            else putchar(' '),writeint(i);
        }
        puts("");
       // n=readint();
    }
    return 0;
}