Input and output optimization optimization

 1 inline int read()
 2 {
 3     int x=0,w=1;char ch=0;
 4     while(!isdigit(ch)){if(ch=='-') w=-1;ch=getchar();}
 5     while(isdigit(ch)) x=(x<<3)+(x<<1)+ch-'0',ch=getchar();
 6     return x*w;
 7 }
 8 int buf[30];
 9 void write(int x)
10 {
11     if(x<0) putchar('-'),x=-x;
12     buf[0]=0;
13     while(x) buf[++buf[0]]=x%10,x/=10;
14     if(!buf[0]) buf[0]=1,buf[1]=0;
15     while(buf[0]) putchar('0'+buf[buf[0]--]);
16 }