15 Puzzle Program, stuck on up left right down commands - c

Question

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main (void){
//Function used to set up your game board
int disp[4][4];
int i, j;
int game_over = 0;
for(i = 0; i < 4; i++) {
for(j = 0;j < 4; j++) {
printf("Enter a value from 1 - 15 for %d %d: ", i, j);
scanf("%d", &disp[i][j]);
}
}
//Function used to display the game board
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
printf(" _ ");
else if (disp[i][j] < 10)
printf(" %d ",disp[i][j]);
else
printf("%d ",disp[i][j]);
}
}
// Function to show where cursor is
for(i = 0; i < 4; i++){
printf("\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
printf("");
}
}
//Skeleton to function to controller
do{
char move[10];
printf("Enter a move: ");
scanf("%s", move);
if (strcmp("up", move) == 0){
for(i = 0; i < 4; i++){
printf("");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i >= 1){
int temp = disp[i][j];
disp[i][j] = disp[i - 1][j];
disp[i - 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("Up", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 1){
int temp = disp[i][j];
disp[i][j] = disp[i - 1][j];
disp[i - 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("UP", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 1){
int temp = disp[i][j];
disp[i][j] = disp[i - 1][j];
disp[i - 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("down", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i < 4){
int temp = disp[i][j];
disp[i][j] = disp[i + 1][j];
disp[i + 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("Down", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i < 4){
int temp = disp[i][j];
disp[i][j] = disp[i + 1][j];
disp[i + 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("DOWN", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i < 4){
int temp = disp[i][j];
disp[i][j] = disp[i + 1][j];
disp[i + 1][j] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("left", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (j >= 1){
int temp = disp[i][j];
disp[i][j] = disp[i][j - 1];
disp[i][j - 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("Left", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 1){
int temp = disp[i][j];
disp[i][j] = disp[i][j + 1];
disp[i][j + 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("LEFT", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 1){
int temp = disp[i][j];
disp[i][j] = disp[i][j + 1];
disp[i][j + 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("right", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (j <= 4){
int temp = disp[i][j];
disp[i][j] = disp[i][j + 1];
disp[i][j + 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("Right", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 4){
int temp = disp[i][j];
disp[i][j] = disp[i][j - 1];
disp[i][j - 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else if (strcmp("RIGHT", move) == 0){
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i > 4){
int temp = disp[i][j];
disp[i][j] = disp[i][j - 1];
disp[i][j - 1] = temp;
}
else {
printf("Invalid move!");
}
}
}
}
else
printf("Invalid Move!");
//Update the board function
for(i = 0; i < 4; i++){
printf("\n\n");
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
printf(" _ ");
else if (disp[i][j] < 10)
printf(" %d ",disp[i][j]);
else
printf("%d ",disp[i][j]);
}
}
}
while (game_over == 0);
return 0;
}
I am having trouble making the cursor go right or down? I can go left and up, but not the other two. I'm not looking for someone to answer the entire program its just I have been stuck on this for hours and every other code I look at sees similar to mine.I can get it to correctly do up and left but right and down cause a problem and not sure why.

Answer 1

The bug is the checking logic is wrong and the bad practice you followed is lots of repetitive code.
Well I have boiled the code to something simple.
...
else if (strcmp("down", move) == 0 || strcmp("Down", move) == 0 || strcmp("DOWN", move) == 0){
int d = 0;
for(i = 0; i < 4; i++){
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if (i+1 < 4){ // <--- notice the change
int temp = disp[i][j];
disp[i][j] = disp[i + 1][j];
disp[i + 1][j] = temp;
d = 1;
break; // <-- and this
}
else {
printf("%s","Invalid move!");
}
}
if( d == 1)
break;
}
}
else if (strcmp("right", move) == 0 || strcmp("Right", move) == 0 || strcmp("RIGHT", move) == 0){
for(i = 0; i < 4; i++){
for(j = 0; j < 4; j++){
if (disp[i][j] == -1)
if ( j+1 < 4){ // <--- notice the change
int temp = disp[i][j];
disp[i][j] = disp[i][j + 1];
disp[i][j + 1] = temp;
break; // <-- and this
}
else {
printf("%s","Invalid move!");
}
}
}
}
...
You can check that there is a break statement in case of down and right. The reason is, when you swap -1 to the right or down then you will meet up again in the loop iteration.
So without the break the result would be
_ 1 2 3
4 5 6 7
8 9 1 2
3 4 5 6
>>> right
1 2 3 _
4 5 6 7
8 9 1 2
3 4 5 6
Another thing is don't repeat code. The readability is worse when you do that. Maintaining the code is even harder. Even better here you can write swap() logic and use it. And also the movement of the tiles can also be done with another function.
Tricky downlogic (Edit-1).
In case of downlogic the simple breaking up the loop wont work because in case you do that there will be a chance that in next iteration it will again get -1 and try to swap it with next number.