/* Checks is either of the stacks used to simulate the queue are empty. Returns
TRUE is both are empty, FALSE if at least one stack contains values.
*/
bool isEmptyQ (Stack *stk1, Stack *stk2)
{
if (!isEmptyS(stk1) || !isEmptyS(stk2))
return false;
else
return true;
}
// Checks to see if the queue is empty
bool isEmptyQ(Queue *q) {
if (q == NULL) {
return true;
}
if (isEmptyS(&(q->stack1)) && isEmptyS(&(q->stack2))) {
return true;
}
return false;
}
void popQ(Stack *s1, Stack *s2, char **c){
char *t;
if(isEmptyS(s2)){
while(!(isEmptyS(s1))){
popS(s1, &t);
pushS(s2, t);
}
}
popS(s2, c);
}
// Removes the string from the front of the queue and sets it to s
void deQ(Queue *q, char **s) {
if (isEmptyQ(q)) {
DIE("Queue is empty");
}
if (!isEmptyS(&(q->stack2))) {
popS(&(q->stack2), s);
}
else {
while (!isEmptyS(&(q->stack1))) {
popS(&(q->stack1), s);
pushS(&(q->stack2), *s);
}
popS(&(q->stack2), s);
}
}
/* Pops off string pointer in FIFO order by taking from Stack 2 if it has
values and otherwise pouring all the values from Stack 1 into Stack 2 before
popping off the top of Stack 2, which will be the first element pushed onto
Stack 1. Returns TRUE if successful and puts popped value into *pos.
*/
bool dequeue (Stack *stk1, Stack *stk2, char **pos)
{
if (!isEmptyQ(stk1, stk2)) // The queue is NOT empty
{
if (!isEmptyS(stk2)) // stk2 has vals, pop off top one
{
popS(stk2, pos);
return true;
}
else // No vals in stk2
{
while (!isEmptyS(stk1)) // pour all of stk1 into stk2
{
popS(stk1, pos);
pushS(stk2, *pos);
}
popS(stk2, pos); // Now pop off top of stk2
return true;
}
}
else
return false; // Queue was empty
}
/*
Function:
quicksort
Arguments:
A = the stack we want to be sorted
B = the stack where we put the bigger values
C = the stack where we put the smaller values
flipped = for keeping the sort stable
location = where the sorted stack is, from 1 to 3
counter = how many values have been pushed on this level
pos = the value of POS
len = the value of LEN
Return Value:
This function returns void
Outside Effect:
This function sorts the values in the A stack, which
persists outside the function
Description:
This function performs quicksort using three stacks
*/
void quicksort(Stack *A, Stack *B, Stack *C, bool flipped,
int location, int counter, int pos, int len) {
// Base case
if (counter == 0) {
return;
}
char *splitter; // The splitter string
// Pop off the splitter
if (!isEmptyS(A)) {
if (!popS(A, &splitter)) {
DIE("Pop failed");
}
counter--;
}
char *next = NULL; // The next string to be sorted
int bigger = 0; // The number of pushes to B
int smaller = 0; // The number of pushes to C
// Split the stack into bigger and smaller
while (counter > 0) {
if (!popS(A, &next)) {
DIE("Pop failed1");
}
int comp; // The value of the comparsion
comp = strcompare(splitter, next, pos, len);
// Push the string to the bigger stack
if (comp < 0) {
if(!pushS(B, next)) {
DIE("Push failed");
}
bigger++;
}
// Push the string to the smaller stack
else if (comp > 0) {
if(!pushS(C, next)) {
DIE("Push failed");
}
smaller++;
}
// If strings are equal, perform stability check
else {
// If flipped, push the splitter
if (flipped) {
if(!pushS(B, splitter)) {
DIE("Push failed");
}
splitter = next;
bigger++;
}
// Otherwise push the string
else {
if(!pushS(B, next)) {
DIE("Push failed");
}
bigger++;
}
}
counter--;
}
// Swap the value of flipped each iteration
flipped = !flipped;
// Recursive step
if (bigger == 0) {
// Push to A, swap location 1 and 2, sort smallers
if (location == 1) {
if(!pushS(A, splitter)) {
DIE("Push failed");
}
if (smaller == 0) {
return;
}
quicksort(C, A, B, flipped, 2, smaller, pos, len);
}
// Push to B, keep location the same, sort smallers
else if (location == 2) {
if(!pushS(B, splitter)) {
DIE("Push failed");
}
if (smaller == 0) {
return;
}
quicksort(C, B, A, flipped, 2, smaller, pos, len);
}
}
else {
// Swap location 1 and 2, sort biggers, push to A, sort smallers
if (location == 1) {
quicksort(B, A, C, flipped, 2, bigger, pos, len);
if(!pushS(A, splitter)) {
DIE("Push failed");
}
if (smaller == 0) {
return;
}
quicksort(C, A, B, flipped, 2, smaller, pos, len);
}
// Keep location the same, sort biggers, push to B, sort smallers
else if (location == 2) {
quicksort(B, A, C, flipped, 1, bigger, pos, len);
if(!pushS(B, splitter)) {
DIE("Push failed");
}
if (smaller == 0) {
return;
}
quicksort(C, B, A, flipped, 2, smaller, pos, len);
}
}
return;
}
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;
}
int main(int argc, char * argv[]){
Stack stack1;
Stack stack2;
Stack stack3;
createS(&stack1);
createS(&stack2);
createS(&stack3);
int flipped = 1; //equals 1 if lines are in same relative order as in files, -1 if flipped
int pos = 0;
int len = INT_MAX;
int filestart = 1; //variable is incremented if there is a len/pos key
int nlines = 0; //Number of lines beeing sorted
char * end;
if( argc == 1 ){
exit(1);
}
if(argv[1][0] == '-'){
filestart +=1;
pos = strtol(&argv[1][1],&end,10);
if(end[0] != ',' && strlen(end) != 0){
DIE("Invalid input");
}
else if (strlen(end) != 0 ){
len = strtol(&end[1],&end,10);
printf("%d", len);
}
if (strlen(end) != 0){
DIE("Invalid input");
}
}
char * line;
FILE * fp;
for(int m=filestart; m < argc; m++) {
if(argv[m][0] == '-'){
fp = stdin;
}
else if ((fp = fopen(argv[m],"r")) == NULL){
DIE("Cannot read file");
}
while((line = getLine(fp)) != NULL){
remove_break(&line);
if(!pushS(&stack1, line)){
DIE("pushS failed to execute");
}
nlines += 1;
}
fclose(fp);
}
split(&stack2, &stack1, &stack3, nlines, pos, len, -1, flipped * -1);
while(!isEmptyS(&stack2)){
popS(&stack2, &line);
printf("%s", line);
free(line);
printf("\n");
}
while(!isEmptyS(&stack1)){
popS(&stack1, &line);
printf("%s", line);
free(line);
printf("\n");
}
destroyS(&stack1);
destroyS(&stack2);
destroyS(&stack3);
return 1;
}
