Output 1 ~ All non-prime numbers within 1000

Output 1 ~ All non-prime numbers within 1000

Luo Weifeng 2011-3-18

I often see the prime number of the questions on the Internet, but I am not very clear about the concept of the prime number. Today I have encountered a problem, so I did it myself. The basic skills are very important, I am not specialized in algorithms. What are my guesses! Don't talk nonsense. paste the following code!

Using system. collections; <br/>/* <br/> question: write a program and output 1 ~ All non-prime numbers within 1000. <Br/> material: prime number. In a natural number greater than 1, except for 1 and the integer itself <br/> cannot be divisible by other natural numbers. In other words, there are only two positive factors (1 and oneself) of the self <br/>, then the number is a prime number. A number larger than 1 but not a prime number is called a union number. 1 and 0 are both non-prime numbers and non-composite numbers. <Br/> Prime Numbers play an important role in number theory <br/> */<br/> namespace noneprime <br/>{< br/> class Program <br/> {<br/> static void main (string [] ARGs) <br/>{< br/> arraylist numberlist = new arraylist (); <br/> for (Int J = 2; j <= 1000; j ++) <br/> {<br/> for (INT I = 2; I <j; I ++) <br/>{< br/> If (J % I = 0 & J! = I) <br/>{< br/> numberlist. add (j); <br/> break; <br/>}< br/> for (int K = 0; k <numberlist. count; k ++) <br/>{< br/> system. console. out. write (numberlist [k] + (K % 10 = 0 & K! = 0? "/N": ""); <br/>}< br/> system. console. readkey (); <br/>}< br/> 

Output result:

4 6 8 9 10 12 14 15 16 18 20 <br/> 21 22 24 25 26 27 28 30 32 33 <br/> 34 35 36 38 39 40 42 44 45 46 <br/> 48 49 50 51 52 54 55 56 57 58 <br/> 60 62 63 64 65 66 68 69 70 72 <br/> 74 75 76 77 78 80 81 82 84 85 <br/> 86 87 88 90 91 92 93 94 95 96 <br/> 98 99 100 102 104 105 106 108 110 <br/> 111 112 114 115 116 117 118 119 120 121 122 <br/> 123 124 125 126 128 129 130 132 133 <br/> 134 135 136 138 140 141 142 143 144 <br/> 145 146 147 148 150 152 153 154 155 156 158 159 <br/> 160 161 162 164 165 166 168 169 170 <br/> 171 172 174 175 176 177 178 180 182 <br/> 183 184 185 186 188 189 190 192 194 195 196 <br/> 198 200 201 202 203 204 205 206 207 <br/> 208 209 210 212 213 214 215 216 217 218 <br/> 219 221 222 224 225 226 228 230 231 232 <br/> 234 235 236 237 238 240 242 243 244 <br/> 245 246 247 248 249 250 252 253 254 255 256 <br/> 258 259 260 261 262 264 265 266 267 268 <br/> 270 272 273 274 275 276 278 279 280 282 <br/> 284 285 286 287 288 289 290 291 292 294 <br/> 295 296 297 298 299 300 301 302 303 304 <br/> 305 306 308 309 310 312 314 315 316 318 <br/> 319 320 321 322 323 324 325 326 327 328 <br/> 329 330 332 333 334 335 336 338 339 <br/> 340 341 342 343 344 345 346 348 350 351 <br/> 352 354 355 356 357 358 360 361 362 363 364 <br/> 365 366 368 369 370 371 372 374 375 <br/> 376 377 378 380 381 382 384 385 386 <br/> 387 388 390 391 392 393 394 395 396 398 399 400 <br/> 402 403 404 405 406 407 408 410 411 <br/> 412 413 414 415 416 417 418 420 422 <br/> 423 424 425 426 428 429 430 432 434 435 436 <br/> 437 438 440 441 442 444 445 446 447 <br/> 448 450 451 452 453 454 455 456 458 459 <br/> 460 464 465 466 468 469 470 471 472 473 <br/> 474 475 476 477 478 480 481 482 483 <br/> 484 485 486 488 489 490 492 493 494 495 496 <br/> 497 498 500 501 502 504 505 506 507 508 <br/> 510 511 512 513 514 515 516 517 518 519 <br/> 520 522 524 525 526 527 528 529 530 531 <br/> 532 533 534 535 536 537 538 539 540 542 <br/> 543 544 545 546 548 549 550 551 552 553 <br/> 554 555 556 558 559 560 561 562 564 565 <br/> 566 567 568 570 572 573 574 575 576 <br/> 578 579 580 581 582 583 584 585 586 588 <br/> 589 590 591 592 594 595 596 597 598 600 602 <br/> 603 604 605 606 608 609 610 611 612 <br/> 614 615 616 618 620 621 622 623 624 <br/> 625 626 627 628 629 630 632 633 634 635 636 637 <br/> 638 639 640 642 644 645 646 648 649 <br/> 650 651 652 654 655 656 657 658 660 <br/> 662 663 664 665 667 668 669 670 671 672 674 <br/> 675 676 678 679 680 681 682 684 685 <br/> 686 687 688 689 690 692 693 694 695 696 <br/> 697 699 700 702 703 704 705 706 707 708 <br/> 710 711 712 713 714 715 716 717 718 <br/> 720 721 722 723 724 725 726 728 729 730 731 <br/> 732 734 735 736 737 738 740 741 742 744 <br/> 745 746 747 748 749 750 752 753 754 755 <br/> 756 758 759 760 762 763 764 765 766 767 <br/> 768 770 771 772 774 775 776 777 778 779 <br/> 780 781 782 783 784 785 786 788 789 790 <br/> 791 792 793 794 795 796 798 799 800 801 <br/> 802 803 804 805 806 807 808 810 812 <br/> 813 814 815 816 817 818 819 820 822 824 <br/> 825 826 828 830 831 832 833 834 835 836 837 <br/> 838 840 841 842 843 844 845 846 847 <br/> 848 849 850 851 852 854 855 856 858 <br/> 860 861 862 864 865 866 867 868 869 870 871 872 <br/> 873 874 875 876 878 879 880 882 884 <br/> 885 886 888 889 890 891 892 893 894 <br/> 895 896 897 898 900 901 902 903 904 905 906 <br/> 908 909 910 912 913 914 915 916 917 <br/> 918 920 921 922 923 924 925 926 927 928 <br/> 930 932 933 934 935 936 938 939 940 942 <br/> 943 944 945 946 948 949 950 951 952 <br/> 954 955 956 957 958 959 960 961 962 963 964 <br/> 965 966 968 969 970 972 973 974 975 976 <br/> 978 979 980 981 982 984 985 986 987 988 <br/> 989 990 992 993 994 995 996 998 999 1000