相关疑难解决方法(0)

matthewmpp@annrogers:~/Programming/C.progs/Personal$ cat prime4.c
/*
 * File:   main.c
 * Author: matthewmpp
 *
 * Created on November 7, 2010, 2:16 PM
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>

/*
prime numbers.
version4
should tell whether a number is prime or not prime.
by using other prime numbers.
 */

int input_func ()
{
    char line[100];
    int n_input;

    while (1) {
        printf("Please enter a whole number.\n");
        fgets(line, sizeof (line), stdin);
        sscanf(line, "%d", &n_input);

        if (n_input >= 0)
            break;

        return (n_input);
    }
} …

在这段代码中:

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>

int main (int argc, char ** argv) {
    uint64_t bignum = 600851475143;
    int is_prime = 0;
    uint64_t result = 0;
    uint64_t i = 0;
    uint64_t j = 0;

    for (i = 0; i < bignum; i++) {
        if (bignum % i == 0) {
            is_prime = 1;
            for (j = 0; j < i; j++) {
                if (i % j == 0) {
                    is_prime = 0;
                    break;
                }
            }
            if (is_prime) {
                result …