[英]how do I add up the sum of the digits of a number except for digits that repeat themselves in c?
我有一个作业,我需要把它的数字相加并忽略一次重复自己,例如 234111 -> 2 + 3 + 4 + 1 -> 10 我试过这样做:#include
int main(void)
{
int i = 0;
int num = 0;
int sum = 0;
printf("Please enter a number\n");
scanf("%d", &num);
while(num > 0){
sum += num%10;
num /= 10;
}
printf("%d", sum);
return 0;
}
我所做的只是将数字相加,它并没有忽略那些重复的数字我需要在代码中添加什么?
您可以保留已使用数字的“标志”数组:
#include <stdio.h>
int main(void)
{
// int i = 0; // You don't actually use this in the code!
int num = 0;
int sum = 0;
int used[10] = { 0, }; // Set all "used" flags to zero
printf("Please enter a number\n");
scanf("%d", &num);
while (num > 0)
{
int digit = num % 10; // Get the digit
if (!used[digit]) sum += digit; // Only add if not used already
used[digit] = 1; // Now we have used it!
num /= 10;
}
printf("%d", sum);
return 0;
}
随时要求进一步澄清和/或解释。
如果您已经看过,只需阅读每个字符并记录:
#include <stdio.h>
#include <ctype.h>
int
main(void)
{
int seen[10] = {0};
int sum = 0;
int c;
while( ( c = getchar()) != EOF ) {
int v = c - '0';
if( isspace(c)) {
continue;
}
if( v < 0 || v > 9 ) {
fprintf(stderr, "Invalid input\n");
return 1;
}
if( ! seen[v]++ )
sum += v;
}
printf("%d\n", sum);
return 0;
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.