algorithm - Finding minimum moves required for making 2 strings equal -

this question 1 of online coding challenge (which has completed).
need logic how approach.

problem statement:
have 2 strings , b same super set of characters. need change these strings obtain 2 equal strings. in each move can perform 1 of following operations:

1. swap 2 consecutive characters of string   2. swap first , last characters of string 

a move can performed on either string.
minimum number of moves need in order obtain 2 equal strings?

input format , constraints:
first , second line of input contains 2 strings , b. guaranteed superset characters equal.

1 <= length(a) = length(b) <= 2000 input characters between 'a' , 'z' 

output format:
print minimum number of moves line of output

sample input: aab baa  sample output: 1 

explanation:
swap first , last character of string aab convert baa. 2 strings equal.

edit : here first try, i'm getting wrong output. can guide me wrong in approach.

int minstringmoves(char* a, char* b) {     int length, pos, i, j, moves=0;     char *ptr;     length = strlen(a);      for(i=0;i<length;i++) {         // find first occurrence of b[i] in         ptr = strchr(a,b[i]);         pos = ptr - a;          // if last element, swap first         if(i==0 && pos == length-1) {             swap(&a[0], &a[length-1]);             moves++;         }         // else swap current index till pos         else {             for(j=pos;j>i;j--) {                 swap(&a[j],&a[j-1]);                 moves++;             }         }          // if equal, break         if(strcmp(a,b) == 0)             break;           }     return moves; } 

take @ example:

aaaaaaaaab abaaaaaaaa 

your solution: 8

aaaaaaaaab -> aaaaaaaaba -> aaaaaaabaa -> aaaaaabaaa -> aaaaabaaaa ->  aaaabaaaaa -> aaabaaaaaa -> aabaaaaaaa -> abaaaaaaaa 

proper solution: 2

aaaaaaaaab -> baaaaaaaaa -> abaaaaaaaa 

you should check if swapping in other direction give better result.

but ruin previous part of string. eg:

caaaaaaaab cbaaaaaaaa  caaaaaaaab -> baaaaaaaac -> abaaaaaaac 

you need swap here put 'c' first place.

the proper algorithm more complex, can see what's wrong in solution.