#include<string.h>
int?str2int(char?*ch);//字符型數字轉整型數字
int?p10(int?m);//計算10的次方，pow函數計算10次方有誤差，重寫函數
int?main()
{
char?ch[]="234";
int?n;
n=str2int(ch);
printf("n=%d\n",n);
return?0;
}
int?str2int(char?*ch)
{
int?len=strlen(ch),i,n=0,m=0;
for(i=len-1;i>=0;i--)
{
n=n+(ch[i]-'0')*p10(m++);
}
return?n;
}
int?p10(int?m)
{
int?i,sum=1;
if(m==0)
return?1;
for(i=0;i<m;i++)
sum=sum*10;
return?sum;
}