this is a program I personally wrote in C to solve the knight's tour problem on an 8 by 8 board with user entering the square ...

here's the prblem ... if you use a1 as the starting square (0, 0 because of 2d array), it will get to h1, where there is only one move, which turns out to be f2 ... but it doesn't move the knight there for some reason (it is supposed to select CASE 6, but it doesn't) ... this happens on move 17 (when the knight is supposed to go to f2) ...

the idea was to have it goto to next possible square (each one) and give it a rating (how many moves are available from that square), then choose the lost rating and move the knight there ... rinse repeat ...

#include <stdio.h>

void getstart(int board[][8], int *row, int *col, int movelist[][2], int *movelist_index);
void makemove(int *row, int *col, int board[][8], int movelist[][2], int *movelist_index);
int nummoves(int row, int col, int board[][8]);

void main()
{
int board[8][8]={0};
int movelist[64][2]={0};
int movelist_index=0;
int row;
int col;
int loop_count;

getstart(board,&row,&col,movelist,&movelist_index);
printf("\nStarting square= %c%d\n",movelist[0][0],movelist[0][1]);

for(loop_count=1;loop_count<63;loop_count++) {
makemove(&row,&col,board,movelist,&movelist_index);
// printf("%c%d\n",movelist[loop_count][0],movelist[loop_count][1]);
printf("%d\t%c%d\n",movelist_index,(movelist[loop_count][0])+97,(movelist[loop_count][1])+1);
}
}

void getstart(int board[][8], int *row, int *col, int movelist[][2], int *movelist_index)
{

printf("Please select the starting move by following the instructions!\n\n");
printf(" 7 a8 b8 c8 d8 e8 f8 g8 h8\n");
printf(" 6 a7 b7 c7 d7 e7 f7 g7 h1\n");
printf("R 5 a6 b6 c6 d6 e6 f6 g6 h1\n");
printf("O 4 a5 b5 c5 d5 e5 f5 g5 h1\n");
printf("W 3 a4 b4 c4 d4 e4 f4 g4 h1\n");
printf("S 2 a3 b3 c3 d3 e3 f3 g3 h1\n");
printf(" 1 a2 b2 c2 d2 e2 f2 g2 h1\n");
printf(" 0 a1 b1 c1 d1 e1 f1 g1 h1\n\n");
printf(" 0 1 2 3 4 5 6 7\n\n");
printf("\t\tCOLUMNS\n");

printf("INSTRUCTIONS:\n");
printf("- look at the square you want to start at\n");
printf("- note the COLUMN and the ROW where it is located\n");
printf("- enter the COLUMN, then the ROW as promted\n\n");

do {
printf("Please enter the COLUMN: ");
scanf("%d",col);

if (*col<0||*col>7) {
printf("COLUMN is out of range, it must be between 0 and 7 inclusively\n");
}

} while (*col<0||*col>7);

do {
printf("Please enter the ROW: ");
scanf("%d",row);

if (*row<0||*row>7) {
printf("ROW is out of range, it must be between 0 and 7 inclusively\n");
}

} while (*row<0||*row>7);

board[*row][*col]=1;

movelist[*movelist_index][0]=((*col)+97);
movelist[*movelist_index][1]=((*row)+1);
(*movelist_index)++;

}

void makemove(int *row, int *col, int board[][8], int movelist[][2], int *movelist_index)
{
int move[8]={0};
int counter;
int temp;
int num_moves=10;

// printf("%d\n",*movelist_index);
if (((*row)-2>=0)&&((*col)-1>=0)&&(board[(*row)-2][(*col)-1]!=1)) {
// printf("move[0] is getting called\n");
move[0]=nummoves((*row)-2,(*col)-1,board);
}

if (((*row)-2>=0)&&((*col)+1<=7)&&(board[(*row)-2][(*col)+1]!=1)) {
move[1]=nummoves((*row)-2,(*col)+1,board);
// printf("move[1] is getting called\n");
}

if (((*row)+2<=7)&&((*col)-1>=0)&&(board[(*row)+2][(*col)-1]!=1)) {
move[2]=nummoves((*row)+2,(*col)-1,board);
// printf("move[2] is getting called\n");
}

if (((*row)+2<=7)&&((*col)+1<=7)&&(board[(*row)+2][(*col)+1]!=1)) {
move[3]=nummoves((*row)+2,(*col)+1,board);
// printf("move[3] is getting called\n");
}

if (((*row)-1>=0)&&((*col)-2>=0)&&(board[(*row)-1][(*col)-2]!=1)) {
move[4]=nummoves((*row)-1,(*col)-2,board);
// printf("move[4] is getting called\n");
}

if (((*row)-1>=0)&&((*col)+2<=7)&&(board[(*row)-1][(*col)+2]!=1)) {
move[5]=nummoves((*row)-1,(*col)+2,board);
// printf("move[5] is getting called\n");
}

if (((*row)+1<=7)&&((*col)-2>=7)&&(board[(*row)+1][(*col)-2]!=1)) {
move[6]=nummoves((*row)+1,(*col)-2,board);
// printf("move[6] is getting called\n");
}

if (((*row)+1<=7)&&((*col)+2<=7)&&(board[(*row)+1][(*col)+2]!=1)) {
move[7]=nummoves((*row)+1,(*col)+2,board);
// printf("move[7] is getting called\n");
}

for(counter=0;counter<=7;counter++) {
if (move[counter]<num_moves&&move[counter]>0) {
temp=counter;
num_moves=move[counter];
}
}

printf("temp=%d\n",temp);

switch (temp) {
case 0:
(*row)-=2;
(*col)-=1;
break;
case 1:
(*row)-=2;
(*col)+=1;
break;
case 2:
(*row)+=2;
(*col)-=1;
break;
case 3:
(*row)+=2;
(*col)+=1;
break;
case 4:
(*row)-=1;
(*col)-=2;
break;
case 5:
(*row)-=1;
(*col)+=2;
break;
case 6:
(*row)+=1;
(*col)-=2;
break;
case 7:
(*row)+=1;
(*col)+=2;
break;
}

board[*row][*col]=1;
movelist[*movelist_index][0]=(*col);
movelist[*movelist_index][1]=(*row);
(*movelist_index)++;

}

int nummoves(int row, int col, int board[][8])
{
int count=0;

if (((row)-2>=0)&&((col)-1>=0)&&(board[row-2][col-1]!=1))
count++;

if (((row)-2>=0)&&((col)+1<=7)&&(board[row-2][col+1]!=1))
count++;

if (((row)+2<=7)&&((col)-1>=0)&&(board[row+2][col-1]!=1))
count++;

if (((row)+2<=7)&&((col)+1<=7)&&(board[row+2][col+1]!=1))
count++;

if (((row)-1>=0)&&((col)-2>=0)&&(board[row-1][col-2]!=1))
count++;

if (((row)-1>=0)&&((col)+2<=7)&&(board[row-1][col+2]!=1))
count++;

if (((row)+1<=7)&&((col)-2>=0)&&(board[row+1][col-2]!=1))
count++;

if (((row)+1<=7)&&((col)+2<=7)&&(board[row+1][col+2]!=1))
count++;

// printf("count= %d\n",count);
return (count);
}