几个C语言程序

冒泡排序

# include <stdio.h>
int main()
{
    int a[10];
    int i,j,t;
    printf("10 numbers ");
    for(i = 0;i < 10;i++){
        scanf("%d",&a[i]);
    }
    printf("\n");
    for(j = 0;j < 9;j++){
        for(i = 0;i < 9-j;i++){
            if(a[i]>a[i+1]){
                t = a[i];
                a[i] = a[i+1];
                a[i+1] = t;
            }
        }
    }
    printf("the sorted numbers: ");
    for(i = 0;i < 10;i++){
        printf("%d",a[i]);
    }
    printf("\n");
}

选择排序

#include<stdio.h>

void sort(int array[], int n)
{
	int i, j, k, t;
	for (i = 0; i < n - 1; i++) {
		k = i;
		for (j = i + 1; j < n; j++) {
			if (array[j] < array[k]) {
				k = j;
			}
		}
		t = array[k];
		array[k] = array[i];
		array[i] = t;
	}
}
int main()
{
	int a[10], i;
	printf("enter array:\n");
	for (i = 0; i < 10; i++) {
		scanf("%d", &a[i]);
	}
	sort(a, 10);
	printf("the sorted array:\n");
	for (i = 0; i < 10; i++) {
		printf("%d ", a[i]);
	}
	printf("\n");
}

字符倒序

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

void inverse(char s[])
{
	int l = strlen(s);
	for (int i = 0; i < l / 2; i++) {
		char t = s[i];
		s[i] = s[l - i - 1];
		s[l - 1 - i] = t;
	}
}

int main()
{
	char s1[100];
	printf("please input string:");
	gets(s1);
	inverse(s1);
	printf("inverse srting:%s", s1);
	printf("\n");
}

指针排两大小

#include<stdio.h>

void swap(int *p1, int *p2)
{
	int t;
	t = *p1;
	*p1 = *p2;
	*p2 = t;
}
int main()
{
	int a, b;
	int *pointer_1,*pointer_2;
	printf("a and b:");
	scanf("%d %d", &a, &b);
	pointer_1 = &a;
	pointer_2 = &b;
	if (a < b) {
		swap(pointer_1, pointer_2);
	}
	printf("max=%d,min=%d", a, b);
	printf("\n");
}

指针排三个数大小

#include <stdio.h>

void swap(int *p1, int *p2)
{
    int t;
    t = *p1;
    *p1 = *p2;
    *p2 = t;
}

int main()
{
    int a, b, c;
    int *s1, *s2, *s3;
    printf("输入3个数:");
    scanf("%d %d %d", &a, &b, &c);
    s1 = &a;
    s2 = &b;
    s3 = &c;
    if (*s1 > *s2)
    {
        swap(s1, s2);
    }
    if (*s1 > *s3)
    {
        swap(s1, s3);
    }
    if (*s2 > *s3)
    {
        swap(s2, s3);
    }
    printf("小到大为: %d %d %d", a, b, c);
    printf("\n");
}

四则计算

#include <stdio.h>

int main()
{
    int a, b;
    double c;
    char op;
    printf("整数a和b和运算符：");
    scanf("%d %d", &a, &b);
    printf("输入运算符：");
    scanf(" %c", &op);

    switch (op)
    {
    case '+':
        printf("a+b=%d\n", (a + b));
        break;
    case '-':
        printf("a-b=%d\n", (a - b));
        break;
    case '*':
        printf("a*b=%d\n", (a * b));
        break;
    case '/':
        if (b == 0)
        {
            printf("除数不能为零！\n");
        }
        else
        {
            printf("a/b=%.2f\n",(double)a / (double)b);
        }
        break;
    default:
        printf("输入的运算符无效！\n");
        break;
    }
}

判断闰年

#include <stdio.h>
int main()
{
    int year;
    printf("请输入年份：");
    scanf("%d", &year);
    if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
        printf("%d 是闰年\n", year);
    else
        printf("%d 不是闰年\n", year);
    return 0;
}