void BFS(int end_row, int end_col)
{
while(Qhead < Qtail)
{
/* printQ(); */
Node *current = popQ();
if(current->row == end_row && current->col == end_col) return;
int i=0;
int array[4] = {NORTH, WEST, EAST, SOUTH};
for(i=0 ; i<4 ; i++){
if(current->linked[array[i]] == 1){
if(array[i]==EAST){
pushQ(current, &maze[current->row][current->col + 1][WEST]);
} else if(array[i]==SOUTH){
pushQ(current, &maze[current->row + 1][current->col][NORTH]);
} else if(array[i]==WEST){
pushQ(current, &maze[current->row][current->col - 1][EAST]);
} else if(array[i]==NORTH) {
pushQ(current, &maze[current->row - 1][current->col][SOUTH]);
} else fprintf(stderr, "WTF?\n");
}
}
}
/* printf("Q runs out!\n"); */
}
int main(int numargs, char *args[]){
//should have either 4, 5, 6, or 7 arguments
//if 7, [1] must be -r, [2,3,4] must be ints, initial and goal are letters
//if 6, must not include -r, include all else
//if 5 must include -r and not height OR width
//if 4, must have int for maxlength and letters for other, and nothing else
//height and width are ints between 2 and 5 (Default is 3)
//maxlength is non-negative int (can be 0)
//INITIAL and GOAL have the necessary number of letters for the size of the tray
//letters between only A and L (duplicates ok)
int width = 3; //width of the tray, default is 3
int height = 3; //height of the tray, default is 3
int maxlength = -1; //maxlength of the pattern
int tilelen; //number of tiles
char *temp;
bool flag; //true is -r is specified
bool used;
char *initial; //initial position
char *goal; //goal position
//if all the command-line args follow the rules for 4 args
if((numargs == 4) && checkNum(args[1]) &&
checkTiles(args[2], args[3])){
maxlength = (int)strtol(args[1], &temp, 10);
tilelen = strlen(args[2]);
flag = false; //no flag present
initial = args[2];
goal = args[3];
}
//if all the command-line args follow the rules for 5 args
else if((numargs == 5) && checkFlag(args[1]) &&
checkNum(args[2]) && checkTiles(args[3], args[4])){
maxlength = (int)strtol(args[2], &temp, 10);
tilelen = strlen(args[3]);
flag = true; //flag present
initial = args[3];
goal = args[4];
}
//if all the command-line args follow the rules for 6 args
else if((numargs == 6) && checkNum(args[1]) &&
checkNum(args[2]) && checkNum(args[3]) &&
checkTiles(args[4], args[5])){
height = (int)strtol(args[1], &temp, 10);
width = (int)strtol(args[2], &temp, 10);
maxlength = (int)strtol(args[3], &temp, 10);
tilelen = strlen(args[4]);
flag = false; //no flag present
initial = args[4];
goal = args[5];
}
//if all the command-line args follow the rules for 7 args
else if((numargs == 7) && checkFlag(args[1]) &&
checkNum(args[2]) && checkNum(args[3]) &&
checkNum(args[4]) && checkTiles(args[5], args[6])){
height = (int)strtol(args[2], &temp, 10);
width = (int)strtol(args[3], &temp, 10);
maxlength = (int)strtol(args[4], &temp, 10);
tilelen = strlen(args[5]);
flag = true; //flag present
initial = args[5];
goal = args[6];
}
else{//invalid command line args
fprintf(stderr, "Invalid command line arguments\n");
exit(1);
}
if((height >= 2) && (height <= 5) &&
(width >= 2) && (width <= 5) &&
(tilelen == height*width)){}
else{//if the height and width aren't right, then quit
fprintf(stderr, "Invalid command line arguments\n");
exit(1);
}
Stack q1; //create the two stacks for the queue
Stack q2;
createS(&q1);
createS(&q2);
char *nextStr; //holds what is popped off queue 'P'
int nextLen; //holds the length of P
Trie root; //root of the trie dictionary
root.len = -1;
root.from = NULL;
for(int k = 0; k < 12; k++)
root.children[k] = NULL;
insert(&root, goal, NULL, 0); //insert root in queue & dictionary
pushS(&q1, goal);
if(!(strcmp(goal, initial))){ //if goal is initial
printf("%s\n", initial);
destroyS(&q1);
destroyS(&q2);
return 0;
}
while(!(isEmptyS(&q1) && isEmptyS(&q2))){ //while queue not empty
popQ(&q1, &q2, &nextStr);
nextLen = lenInTrie(&root, nextStr);
used = false;
if(nextLen < maxlength){
//generate all the possible tiles
for(int c = 0; c < width; c++){ //for all column shifts
if(flag){//-r, then do it for all possible shifts
for(int sh = 1; sh < width; sh++){
char *nextTiles = shiftC(nextStr, height, width, c, height - sh);
//next tile pattern generated by a shift
if(!strcmp(nextTiles, initial)){
insert(&root, nextTiles, nextStr, nextLen + 1);
printSteps(root, nextTiles);
destroyS(&q1);
destroyS(&q2);
return 0;
}
if(insert(&root, nextTiles, nextStr, nextLen + 1)){
pushS(&q1, nextTiles); //add it to the queue and dictionary
used = true;
}
else
free(nextTiles);
}
}
else{//else do it for shift is one step only
char *nextTiles = shiftC(nextStr, height, width, c, height - 1);
//next tile pattern generated by a shift
if(!strcmp(nextTiles, initial)){
insert(&root, nextTiles, nextStr, nextLen + 1);
printSteps(root, nextTiles);
destroyS(&q1);
destroyS(&q2);
return 0;
}
if(insert(&root, nextTiles, nextStr, nextLen + 1)){
pushS(&q1, nextTiles); //add it to the queue and dictionary
used = true;
}
else
free(nextTiles);
}
}
for(int r = 0; r < height; r++){//for all possible row shifts
if(flag){//-r, then do it for all possible shifts
for(int sh = 1; sh < height; sh++){
char *nextTiles = shiftR(nextStr, height, width, r, width - sh);
//next tile pattern generated by a shift
if(!strcmp(nextTiles, initial)){
insert(&root, nextTiles, nextStr, nextLen + 1);
printSteps(root, nextTiles);
destroyS(&q1);
destroyS(&q2);
return 0;
}
if(insert(&root, nextTiles, nextStr, nextLen + 1)){
pushS(&q1, nextTiles); //add it to the queue and dictionary
used = true;
}
else
free(nextTiles);
}
}
else{//else do it for shift is one step only
char *nextTiles = shiftR(nextStr, height, width, r, width - 1);
//next tile pattern generated by a shift
if(!strcmp(nextTiles, initial)){
insert(&root, nextTiles, nextStr, nextLen + 1);
printSteps(root, nextTiles);
destroyS(&q1);
destroyS(&q2);
return 0;
}
if(insert(&root, nextTiles, nextStr, nextLen + 1)){
pushS(&q1, nextTiles); //add it to the queue and dictionary
used = true;
}
else
free(nextTiles);
}
}
}
if(!used)
free(nextStr);
}//end of while queue is not empty
destroyS(&q1);
destroyS(&q2);
return 0;
}
