57 date: 2021.3.14
Key points:
IsPrime () Judgment prime number
The detailed code is as follows:
#include <conio.h>
#include <stdio.h>
/*************found**************/
int IsPrime(int n)
{
int i,m;
m=1;
for(i=2;i<n;i++)
/*************found**************/
if(!(n%i))
{
m=0;
break;
}
return(m);
}
void main()
{
int j,k;
printf("\nPlease enter an interger number between 2 and 10000: ");
scanf("%d",&k);
printf("\nThe prime factor(s) of %d is(are): ",k);
for(j=2;j<k;j++)
if((!(k%j)) && (IsPrime(j)))
printf("%4d,",j);
printf("\n");
}
Key point:
the usage scenarios of the pointing operator member operator are different
The detailed code is as follows:
#include<stdio.h>
#include<string.h>
#include<conio.h>
#include<stdlib.h>
#define N 10
typedef struct ss /*定义结构体*/
{
char num[10];
int s;
} STU;
void fun(STU a[], STU *s)
{
/*
analyse:
找出成绩最高的学生记录->通过形参返回主函数(只有一个最高分)
*/
//指向运算符 成员运算符 题中"s -> s"等价于 （*s).s
int i;
*s = a[0];
for(i = 0; i<N; i++)
{
if(s->s < a[i].s)
*s =a[i];
}
/* ERROR:
int i,j = 0,max = a[0].s;
for(i = 0; i< N; i++)
{
if(a[i].s >= max)
max = a[i].s;
}
*s = a[i];
*/
}
void main()
{
FILE *wf;
STU a[N]={
{
"A01",81},{
"A02",89},{
"A03",66},{
"A04",87},{
"A05",77},
{
"A06",90},{
"A07",79},{
"A08",61},{
"A09",80},{
"A10",71}},m;
int i;
system("CLS");
printf("*****The original data*****");
for(i=0;i<N;i++)
printf("No=%s Mark=%d\n", a[i].num,a[i].s);
fun(a,&m);
printf("*****THE RESULT*****\n");
printf("The top :%s, %d\n",m.num,m.s);
/******************************/
wf=fopen("out.dat","w");
fprintf(wf,"%s,%d",m.num,m.s);
fclose(wf);
/*****************************/
}