Problem : want similar combinations like .... "201 X 103 = 20703" reverse it to get "30702 = 301 X 102"

1.201 X 103 = 20703 1.30702 = 301 X 102 2.201 X 104 = 20904 2.40902 = 401 X 102 3.201 X 112 = 22512 3.21522 = 211 X 102 4.201 X 113 = 22713 4.31722 = 311 X 102 5.201 X 114 = 22914 5.41922 = 411 X 102 6.201 X 122 = 24522 6.22542 = 221 X 102 7.201 X 123 = 24723 7.32742 = 321 X 102 8.201 X 124 = 24924 8.42942 = 421 X 102 9.201 X 132 = 26532 9.23562 = 231 X 102 10.201 X 133 = 26733 10.33762 = 331 X 102 11.201 X 134 = 26934 11.43962 = 431 X 102 12.201 X 142 = 28542 12.24582 = 241 X 102 13.201 X 143 = 28743 13.34782 = 341 X 102 14.201 X 144 = 28944 14.44982 = 441 X 102 15.201 X 203 = 40803 15.30804 = 302 X 102 16.201 X 211 = 42411 16.11424 = 112 X 102 17.201 X 213 = 42813 17.31824 = 312 X 102 18.201 X 221 = 44421 18.12444 = 122 X 102 19.201 X 223 = 44823 19.32844 = 322 X 102 20.201 X 231 = 46431 20.13464 = 132 X 102 21.201 X 233 = 46833 21.33864 = 332 X 102 22.201 X 241 = 48441 22.14484 = 142 X 102 23.201 X 243 = 48843 23.34884 = 342 X 102 24.201 X 301 = 60501 24.10506 = 103 X 102 25.201 X 302 = 60702 25.20706 = 203 X 102 26.201 X 311 = 62511 26.11526 = 113 X 102 27.201 X 312 = 62712 27.21726 = 213 X 102 28.201 X 321 = 64521 28.12546 = 123 X 102 29.201 X 322 = 64722 29.22746 = 223 X 102 30.201 X 331 = 66531 30.13566 = 133 X 102 31.201 X 332 = 66732 31.23766 = 233 X 102 32.201 X 341 = 68541 32.14586 = 143 X 102 33.201 X 342 = 68742 33.24786 = 243 X 102 34.201 X 401 = 80601 34.10608 = 104 X 102 35.201 X 402 = 80802 35.20808 = 204 X 102 36.201 X 411 = 82611 36.11628 = 114 X 102 37.201 X 412 = 82812 37.21828 = 214 X 102 38.201 X 421 = 84621 38.12648 = 124 X 102 39.201 X 422 = 84822 39.22848 = 224 X 102 40.201 X 431 = 86631 40.13668 = 134 X 102 41.201 X 432 = 86832 41.23868 = 234 X 102 42.201 X 441 = 88641 42.14688 = 144 X 102 43.201 X 442 = 88842 43.24888 = 244 X 102 44.203 X 102 = 20706 44.60702 = 201 X 302 45.203 X 103 = 20909 45.90902 = 301 X 302 46.203 X 112 = 22736 46.63722 = 211 X 302 47.203 X 113 = 22939 47.93922 = 311 X 302 48.203 X 122 = 24766 48.66742 = 221 X 302 49.203 X 123 = 24969 49.96942 = 321 X 302 50.203 X 132 = 26796 50.69762 = 231 X 302 51.203 X 133 = 26999 51.99962 = 331 X 302 52.203 X 211 = 42833 52.33824 = 112 X 302 53.203 X 221 = 44863 53.36844 = 122 X 302 54.203 X 231 = 46893 54.39864 = 132 X 302 55.204 X 102 = 20808 55.80802 = 201 X 402 56.204 X 112 = 22848 56.84822 = 211 X 402 57.204 X 122 = 24888 57.88842 = 221 X 402 58.211 X 102 = 21522 58.22512 = 201 X 112 59.211 X 103 = 21733 59.33712 = 301 X 112 60.211 X 104 = 21944 60.44912 = 401 X 112 61.211 X 113 = 23843 61.34832 = 311 X 112 62.211 X 122 = 25742 62.24752 = 221 X 112 63.211 X 123 = 25953 63.35952 = 321 X 112 64.211 X 132 = 27852 64.25872 = 231 X 112 65.211 X 142 = 29962 65.26992 = 241 X 112 66.211 X 213 = 44943 66.34944 = 312 X 112 67.211 X 221 = 46631 67.13664 = 122 X 112 68.211 X 231 = 48741 68.14784 = 132 X 112 69.211 X 301 = 63511 69.11536 = 103 X 112 70.211 X 302 = 63722 70.22736 = 203 X 112 71.211 X 311 = 65621 71.12656 = 113 X 112 72.211 X 312 = 65832 72.23856 = 213 X 112 73.211 X 321 = 67731 73.13776 = 123 X 112 74.211 X 322 = 67942 74.24976 = 223 X 112 75.211 X 331 = 69841 75.14896 = 133 X 112 76.211 X 401 = 84611 76.11648 = 104 X 112 77.211 X 402 = 84822 77.22848 = 204 X 112 78.211 X 411 = 86721 78.12768 = 114 X 112 79.211 X 412 = 86932 79.23968 = 214 X 112 80.211 X 421 = 88831 80.13888 = 124 X 112 81.213 X 102 = 21726 81.62712 = 201 X 312 82.213 X 103 = 21939 82.93912 = 301 X 312 83.213 X 112 = 23856 83.65832 = 211 X 312 84.213 X 122 = 25986 84.68952 = 221 X 312 85.214 X 102 = 21828 85.82812 = 201 X 412 86.214 X 112 = 23968 86.86932 = 211 X 412 87.221 X 102 = 22542 87.24522 = 201 X 122 88.221 X 103 = 22763 88.36722 = 301 X 122 89.221 X 104 = 22984 89.48922 = 401 X 122 90.221 X 112 = 24752 90.25742 = 211 X 122 91.221 X 113 = 24973 91.37942 = 311 X 122 92.221 X 301 = 66521 92.12566 = 103 X 122 93.221 X 302 = 66742 93.24766 = 203 X 122 94.221 X 311 = 68731 94.13786 = 113 X 122 95.221 X 312 = 68952 95.25986 = 213 X 122 96.221 X 401 = 88621 96.12688 = 104 X 122 97.221 X 402 = 88842 97.24888 = 204 X 122 98.223 X 102 = 22746 98.64722 = 201 X 322 99.223 X 103 = 22969 99.96922 = 301 X 322 100.223 X 112 = 24976 100.67942 = 211 X 322 101.224 X 102 = 22848 101.84822 = 201 X 422 102.231 X 102 = 23562 102.26532 = 201 X 132 103.231 X 103 = 23793 103.39732 = 301 X 132 104.231 X 112 = 25872 104.27852 = 211 X 132 105.231 X 301 = 69531 105.13596 = 103 X 132 106.231 X 302 = 69762 106.26796 = 203 X 132 107.233 X 102 = 23766 107.66732 = 201 X 332 108.233 X 103 = 23999 108.99932 = 301 X 332 109.234 X 102 = 23868 109.86832 = 201 X 432 110.241 X 102 = 24582 110.28542 = 201 X 142 111.241 X 112 = 26992 111.29962 = 211 X 142 112.243 X 102 = 24786 112.68742 = 201 X 342 113.244 X 102 = 24888 113.88842 = 201 X 442 114.301 X 102 = 30702 114.20703 = 201 X 103 115.301 X 112 = 33712 115.21733 = 211 X 103 116.301 X 122 = 36722 116.22763 = 221 X 103 117.301 X 132 = 39732 117.23793 = 231 X 103 118.301 X 302 = 90902 118.20909 = 203 X 103 119.301 X 311 = 93611 119.11639 = 113 X 103 120.301 X 312 = 93912 120.21939 = 213 X 103 121.301 X 321 = 96621 121.12669 = 123 X 103 122.301 X 322 = 96922 122.22969 = 223 X 103 123.301 X 331 = 99631 123.13699 = 133 X 103 124.301 X 332 = 99932 124.23999 = 233 X 103 125.302 X 102 = 30804 125.40803 = 201 X 203 126.302 X 112 = 33824 126.42833 = 211 X 203 127.302 X 122 = 36844 127.44863 = 221 X 203 128.302 X 132 = 39864 128.46893 = 231 X 203 129.302 X 311 = 93922 129.22939 = 113 X 203 130.302 X 321 = 96942 130.24969 = 123 X 203 131.302 X 331 = 99962 131.26999 = 133 X 203 132.311 X 102 = 31722 132.22713 = 201 X 113 133.311 X 112 = 34832 133.23843 = 211 X 113 134.311 X 122 = 37942 134.24973 = 221 X 113 135.311 X 321 = 99831 135.13899 = 123 X 113 136.312 X 102 = 31824 136.42813 = 201 X 213 137.312 X 112 = 34944 137.44943 = 211 X 213 138.321 X 102 = 32742 138.24723 = 201 X 123 139.321 X 112 = 35952 139.25953 = 211 X 123 140.322 X 102 = 32844 140.44823 = 201 X 223 141.331 X 102 = 33762 141.26733 = 201 X 133 142.332 X 102 = 33864 142.46833 = 201 X 233 143.341 X 102 = 34782 143.28743 = 201 X 143 144.342 X 102 = 34884 144.48843 = 201 X 243 145.401 X 102 = 40902 145.20904 = 201 X 104 146.401 X 112 = 44912 146.21944 = 211 X 104 147.401 X 122 = 48922 147.22984 = 221 X 104 148.411 X 102 = 41922 148.22914 = 201 X 114 149.421 X 102 = 42942 149.24924 = 201 X 124 150.431 X 102 = 43962 150.26934 = 201 X 134 151.441 X 102 = 44982 151.28944 = 201 X 144

code to get these combinations: int counter = 1; List<int> firsts = new List<int>(); List<int> seconds = new List<int>(); string result = string.Empty; int x, y, z, p, q, r; int yyyy; for (x = 200; x < 1000; x++) { for (y = 100; y < 1000; y++) { if (x != y) { if (x % 10 != 0) { if (y % 10 != 0) { p = int.Parse(new string(x.ToString().ToCharArray().Reverse().ToArray())); q = int.Parse(new string(y.ToString().ToCharArray().Reverse().ToArray())); if (p != x) { if (q != y) { r = (p * q); z = int.Parse(new string((x * y).ToString().ToCharArray().Reverse().ToArray())); yyyy = x * y ; if (yyyy != z) { if (z == r) { bool toadd = true; for (int aa = 0 ; aa < firsts.Count; aa++) { if ((firsts[aa] == y) && (seconds[aa] == x)) { toadd = false; break; } } if (toadd) { firsts.Add(x); seconds.Add(y); result += counter.ToString() + "." + x.ToString() + " X " + y.ToString() + " = " + (x * y).ToString() + "\r\n"; result += counter.ToString() + "." + r.ToString() + " = " + q.ToString() + " X " + p.ToString() + "\r\n"; counter++; } } } } } } } } } } textBox2.Text = result;