777. Exchange adjacent characters in LR string

777. stay LR Exchange adjacent characters in a string

In a ‘L’ , ‘R’ and ‘X’ A string of three characters （ for example "RXXLRXRXL"） In the mobile operation . One move at a time refers to the use of one "LX" Replacing a "XL", Or use a "XR" Replacing a "RX". Now let's give the starting string start And the ending string end, Please write the code , If and only if there is a series of move operations to make start It can be converted into end when , return True.

Example :

Input : start = “RXXLRXRXL”, end = “XRLXXRRLX”
Output : True
explain :
We can use the following steps to start convert to end:
RXXLRXRXL ->
XRXLRXRXL ->
XRLXRXRXL ->
XRLXXRRXL ->
XRLXXRRLX

The solution code is as follows ：

void swap(char *s,int i1,int i2){
    
    char p=s[i1];
    s[i1]=s[i2];
    s[i2]=p;
}

int find_R(char *s){
    
    int i=0;
    while(s[i]!='\0'){
    

        if(s[i]=='X'){
    
            i++;
        }
        if(s[i]!='X'){
    
            if(s[i]=='R'){
    
                return i;

            }
            return -1;
        }
    }
    return -1;
}

int find_X(char *s){
    
    int i=0;
    while(s[i]!='\0'){
    

        if(s[i]=='L'){
    
            i++;
        }
        if(s[i]!='L'){
    
            if(s[i]=='X'){
    
                return i;

            }
            return -1;
        }
    }
    return -1;
}

bool canTransform(char * start, char * end){
    

    int s=0,e=0,i=0;
    int sx=0;
  
    while(start[s]!='\0'){
    
         // printf("--%s %s ",start,end);
        if(start[s]=='R'){
    
            if(end[e]=='R'){
    
                s++;
                e++;
              
            }
            else{
    
                if(end[e]!='X'){
    
                    return false;
                }
                int i=find_R(end+e+1);
                if(i==-1)
                return false;
                    swap(end,e,e+i+1);
            }
        }
        
        if(start[s]=='X'){
    
            if(end[s]=='X'){
    
                s++;
                e++;
               
             
            }
            else{
    
                 if(end[e]!='L'){
    
                    return false;
                }
                int i=find_X(end+e+1);
                 if(i==-1)
                return false;

              
                 swap(end,e,e+i+1);
                   
                 
                

        }
        }
        if(start[s]=='L'){
    
            if(end[e]=='L'){
    
                e++;
                s++;
                
            }
            else{
    
                return false;
            }
        }
    
        
    }
    printf("%s %s",start,end);
    
    
   return true;;
}