The first occurrence character

Tag: the first occurrence character

Use a hash table. STL does not have a hash container. You can create one by yourself with a total of 256 characters. It is easy to create one.

Code:

# Include <iostream> // the first occurrence character using namespace STD; char findchar (char * pstring) {If (pstring = NULL) return '\ 0 '; const int tablesize = 256; unsigned int hashtable [tablesize]; for (INT I = 0; I <tablesize; I ++) {hashtable [I] = 0 ;} char * phashkey = pstring; while (* phashkey! = '\ 0') {hashtable [* (phashkey ++)] ++;} phashkey = pstring; while (* phashkey! = '\ 0') {If (hashtable [* phashkey] = 1) {return * phashkey;} phashkey ++;} return' \ 0';} int main () {char STR [] = "aabbfccfg"; cout <findchar (STR); Return 0 ;}