#include <stdio.h>
#include <stdlib.h>
int char2Int(char a){
if(a<='9' && a>='0')
return a-'0';
return -1;
}
int getDigit(char * s, int n)
{
int dotPosition = 0;
int len = 0;
for(len = 0;s[len] != '\0';len++);
for(dotPosition = 0;s[dotPosition] != '.';dotPosition++);
if(n == 0 || n< dotPosition *-1 || n > len - dotPosition - 1){
return -1;
}
if(n > 0)
{
return char2Int(s[ n + dotPosition ]);
}
else{
return char2Int(s[ n + dotPosition ]);
}
}
int main(){
printf("输入小数\n");
char number[64];
scanf("%s",number);
int i;
printf("输入位数\n");
scanf("%d",&i);
printf("%d\n",getDigit(number,i));
}
这是源代码,不明白可追问。