输入挂（减少时间）

int

int Scan()

{

    int res = 0, ch, flag = 0;

    if((ch = getchar()) == '-')             //判断正负

        flag = 1;

    else if(ch >= '0' && ch <= '9')           //得到完整的数

        res = ch - '0';

    while((ch = getchar()) >= '0' && ch <= '9' )

        res = res * 10 + ch - '0';

    return flag ? -res : res;

}

double

int re(double *ret)
{  
    int sgn;  
    double bit=0.1;  
    char c;  
    c=getchar();  
    if(c==EOF)return true;  
    while(c!='-'&&c!='.'&&(c<'0'||c>'9'))c=getchar();  
    sgn=(c=='-')?-1:1;  
    *ret=(c=='-')?0:(c-'0');  
    while((c=getchar())>='0'&&c<='9')*ret=*ret*10+(c-'0');  
    if(c==' '||c=='
'){*ret*=sgn;return true;}  
    while((c=getchar())>='0'&&c<='9')*ret+=(c-'0')*bit,bit/=10;  
    *ret*=sgn;  
    return false;  
} 

zifu