I'm trying to output multiple sudoku solutions in my program. For example, when You enter this as input: 8..6..9.5.............2.31...7318.6.24.....73...........279.1..5...8..36..3...... .'s denote blank spaces. Numbers represent already-filled spaces. The output should be a sudoku solution like so: 814637925325149687796825314957318462241956873638274591462793158579481236183562749 However, I want to output multiple solutions. This would be all the solutions that should be printed: 814637925325149687796825314957318462241956873638274591462793158579481236183562749 814637925325941687796825314957318462241569873638472591462793158579184236183256749 834671925125839647796425318957318462241956873368247591682793154579184236413562789 834671925125839647796524318957318462241956873368247591682793154519482736473165289 834671925125839647796524318957318462241965873368247591682793154519482736473156289 But my program only prints out one solution. Below is my recursive solution to solving a sudoku solution bool sodoku::testTheNumber(sodoku *arr[9][9], int row, int column) { if(column == 9) { column = 0; row++; if(row == 9) return true; } if(arr[row][column]->number != 0) { return testTheNumber(arr, row, column+1); } for(int k = 1; k < 10; k++) { if(k == 10) { arr[row][column]->number = 0; return false; } if(rowIsValid(arr, k, row) && columnIsValid(arr, k, column) && boxIsValid(arr, k, row, column)) { arr[row][column]->number = k; if(testTheNumber(arr, row, column+1)==true) { return true; } arr[row][column]->number = 0; } } return false; } Could anyone help me come up with a way to print out multiple solutions? Thanks.