#include<stdio.h>
#include<string.h>
void calculate(char *a, int i, int n);
void swap (char *x, char *y);
int m = 0;
int main(){
char str[10] = "IoT";
int len
=0,i
=0; len
= strlen(str
); calculate
(str
, 0, len
-1); printf("%d\n",m
);}
void swap (char *x, char *y) {
char temp;
temp =*x;
*x=*y;
*y = temp;
}
void calculate(char *a, int i, int n) {
int j =0;
if (i == n){
m++ ;
}
else{
for (j=i; j<=n; j++){
swap((a+i), (a+j));
calculate(a, i+1, n);
swap((a+i), (a+j));
}}}
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