经典C语言源代码
经典C语言源代码
1、(1)某年某月某日是星期几
#include
int main()
{
int year, month, day;
while (scanf_s("%d%d%d", &year, &month, &day) != EOF)
{
if (month == 1 || month == 2)//判断month是否为1或2
{
year--;
month += 12;
}
int c = year / 100;
int y = year - c * 100;
int week = (c / 4) - 2 * c + (y + y / 4) + (13 * (month + 1) / 5) + day - 1;
while (week<0) { week += 7; }
week %= 7;
switch (week)
{
case 1:printf("Monday\n"); break;
case 2:printf("Tuesday\n"); break;
case 3:printf("Wednesday\n"); break;
case 4:printf("Thursday\n"); break;
case 5:printf("Friday\n"); break;
case 6:printf("Saturday\n"); break;
case 0:printf("Sunday\n"); break;
}
}
return 0;
}
1、(2)某年某月某日是第几天（一维数组）
#include "stdio.h"
void main() {
int i, flag, year, month, day, dayth;
int month_day[] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };
printf("请输入年/月/日：\n");
scanf_s("%d/%d/%d", &year, &month, &day);
dayth = day;
flag = (year % 400 == 0) || (year % 4 == 0 && year % 100 != 0);
if (flag)
month_day[2] = 29;
for (i = 1; i < month; i++)
dayth = dayth + month_day[i];
printf("%d/%d/%d是第%d天\n", year, month, day, dayth); }
2、30个数中找最小的数及其位置
#include "stdio.h"
# define SIZE 30
void main() {
int i;
float data[SIZE];
int min;
printf("请输入%d个浮点数：\n",SIZE);
for (i = 0; i < SIZE; i++) {
//scanf_s("%f", &data[i]);
data[i] = rand() % 30 + 1;
printf("%f、", data[i]);
}
min = 0;
for (i = 1; i < SIZE; i++) {
if (data[i] < data[min])
min = i;
}
printf("最小值是%5.2f,位置是%5d\n", data[min], min); }
3、30个数从小到大排序
（1）
#include "stdio.h"
# define SIZE 30
void main() {
int i,j;
float data[SIZE],temp;
int min;
printf("请输入%d个整型数：\n",SIZE);
for (i = 0; i < SIZE; i++) {
scanf_s("%f", &data[i]);
}
for (i = 0; i < SIZE; i++) {
min = i;
for (j = i + 1; j < SIZE; j++)
if (data[j] < data[min])
min = j;
temp = data[min];
data[min] = data[i];
data[i] = temp;
}
printf("\n排序后的结果是：\n");
for (i = 0; i < SIZE; i++)
printf("%5.2f", data[i]);
}
（2）模块化程序（数组名作为函数参数）#include "stdio.h"
# define SIZE 5
void accept_array(float a[], int size);
void sort(float a[], int size);
void show_array(float a[], int size);
void main() {
float score[SIZE];
accept_array(score, SIZE);
printf("排序前：");
show_array(score, SIZE);
sort(score, SIZE);
printf("排序后：");
show_array(score, SIZE);
}
void accept_array(float a[], int size) { int i;
printf("请输入%d个分数：", size);
for (i = 0; i < size; i++)
scanf_s("%f", &a[i]);
}
void show_array(float a[], int size) { int i;
for (i = 0; i < size; i++)
printf(" %5.2f", a[i]);
printf("\n");
}
void sort(float a[],int size) {
int i, min, j;
float temp;
for (i = 0; i < SIZE; i++) {
min = i;
for (j = i + 1; j < SIZE; j++)
if (a[j] < a[min])
min = j;
temp = a[min];
a[min] = a[i];
a[i] = temp;
}
}
4、（1）指针加减：
#include "stdio.h"
#define SIZE 10
void main() {
int a[SIZE] = { 1,2,3,4,5,6,7,8,9,10 };
int *pa, i;
pa = &a[0];
//pa=a;
printf("\n");
for (i = 0; i < SIZE; i++) {
printf(" %d", *pa);
//printf(" %d", *(pa+1));
pa++;
}