问题
I want to remove all the repeated characters from a string. For example, if I have:
"abcdabef"
I want the result to be
"cdef"
I have tried with loops, but it's getting me confusing. Can anyone just tell me how to do this?
Here's what I've tried so far:
#include<stdio.h>
#include<string.h>
main()
{
char s[20],ch,*p;
int i,j,k,cnt;
puts("enter string:");
gets(s);
for(i=0;s[i];i++)
{
ch=s[i];
for(cnt=0,j=0;s[j];j++)
{
if(ch==s[j])
cnt++;
if(cnt>1)
{
for(k=0;s[k]==ch;k++)
{
strcpy(s+k,s+k+1);
if(s[k]==ch)
{k--;}
}
if(s[j-1]==ch)
j--;
}
}
}
puts(s);
}
回答1:
If I were you, I would just count the characters in the string and print out those which appear exactly once in the string.
char buf[BUFSIZE]; // whatever the size is
// get user input
if (!fgets(buf, sizeof buf, stdin))
exit(EXIT_FAILURE); // couldn't fgets()
size_t len = strlen(buf);
int counts[1 << CHAR_BIT] = { 0 };
// count each character
for (size_t i = 0; i < len; i++) {
unsigned char ch = buf[i];
counts[ch]++;
}
// print those which are present exactly once
for (size_t i = 0; i < 1 << CHAR_BIT; i++) {
if (counts[i] == 1) {
printf("%c", (unsigned char)(i));
}
}
回答2:
char* remRepeatedChars(char *str)
{
char arr[128] = {0};
char *tmp = str;
while((*str) != '\0')
{
char *p = str;
while(arr[*p] != 0 && *p != '\0')
p++; // found repetition
if(str != p) // the previous while was entered
*str = *p; //Copy the content of p to str.
arr[*str]++;
str++;
}
return tmp;
}
来源:https://stackoverflow.com/questions/23460454/removing-all-repeated-characters-from-string-in-c