题解 | #[NOIP2008]ISBN号码#
[NOIP2008]ISBN号码
https://www.nowcoder.com/practice/95712f695f27434b9703394c98b78ee5
#include <stdio.h>
int main()
{
//录入字符串
char ch[20] = { 0 };
char* pc = ch;
scanf("%s", pc);
//计算九位数字与(1,2,3,...,9)乘积的和
//i是为了让数字往后推
int i = 0;
int sum = 0;
//而j就是1，2，....，9
//每计算一次就++
int j = 1;
for (i = 0; i < 11; i++)
{
if (*(pc + i) != '-')
{
//数字字符 - '0' <==> 整型的值
sum += (*(pc + i) - '0') * j;
j++;
}
}
//计算最后的标识码的整型数值
int n = sum % 11;
//用m来代替最后的识别码
char m = 0;
if (n >= 0 && n <= 9)
{
m = n + '0';
}
else
{
m = 'X';
}
if (m + 0 == *(pc + 12) + 0)
{
printf("Right\n");
}
else
{
*(pc + 12) = m;
printf("%s", pc);
}
return 0;
}