8个基础且实用的C语言经典实例【附源码】

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"

int main() {
    int i, j, result;

    for (i = 1; i < 10; i++) {
        for (j = 1; j <= i; j++) {
            result = i * j;
            printf("%d*%d=%-4d", i, j, result);
        }
        printf("\n");
    }
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"

int main() {

    long f1, f2;
    int i;
    f1 = f2 = 1;

    for (i = 1; i <= 20; i++) {
        printf("%12ld %12ld", f1, f2);

        if (i % 2 == 0) printf("\n");/*控制输出，每行四个*/

        f1 = f1 + f2; /*前两个月加起来赋值给第三个月*/

        f2 = f1 + f2; /*前两个月加起来赋值给第三个月*/
    }
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"
#include "math.h"

int main() {

    int m, i, k, h = 0, leap = 1;
    printf("\n");

    for (m = 101; m <= 200; m++) {
        k = sqrt(m + 1);
        for (i = 2; i <= k; i++)
            if (m % i == 0) {
                leap = 0;
                break;
            }
        if (leap) /*内循环结束后，leap依然为1，则m是素数*/
        {
            printf("%-4d", m);
            h++;
            if (h % 10 == 0)
                printf("\n");
        }
        leap = 1;
    }
    printf("\nThe total is %d", h);
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"

int main() {
    static int k[10];
    int i, j, n, s;
    for (j = 2; j < 1000; j++) {
        n = -1;
        s = j;
        for (i = 1; i < j; i++) {
            if ((j % i) == 0) {
                n++;
                s = s - i;
                k[n] = i;
            }
        }
        if (s == 0) {
            printf("%d is a 完数: ", j);
            for (i = 0; i < n; i++)
                printf("%d,", k[i]);
            printf("%d\n", k[n]);
        }
    }
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"

int main() {
    int i, j, a[6][6];

    for (i = 0; i <= 5; i++) {
        a[i][i] = 1;
        a[i][0] = 1;
    }

    for (i = 2; i <= 5; i++)

        for (j = 1; j <= i - 1; j++)

            a[i][j] = a[i - 1][j] + a[i - 1][j - 1];

    for (i = 0; i <= 5; i++) {
        for (j = 0; j <= i; j++)

            printf("%4d", a[i][j]);

        printf("\n");
    }
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"
#include <string.h>

int main() {
    char c[200], c1;
    int i, j, k;
    printf("Enter a string: ");
    scanf("%s", c);
    k = strlen(c);

    for (i = 0, j = k - 1; i < k / 2; i++, j--) {
        c1 = c[i];
        c[i] = c[j];
        c[j] = c1;
    }
    printf("%s\n", c);
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include "stdio.h"
#include <string.h>

int main() {
    char s1[6] = "thisis";
    char s2[5] = "is";

    printf("%d\n", search(s1, s2));
    return 0;
}

int search(char s1[], char s2[]) {
    int i = 0, j, len = strlen(s2);

    while (s1[i]) {
        for (j = 0; j < len; j++)
            if (s1[i + j] != s2[j]) break;
        if (j >= len)return i;
        else i++;
    }
    return -1;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include <stdio.h>
#include <string.h>
#include<string.h>

int main() {
    char s[100];
    int i, j, n;

    printf("输入字符串：\n");
    gets(s);
    n = strlen(s);
    for (i = 0, j = n - 1; i < j; i++, j--)
        if (s[i] != s[j]) break;
    if (i >= j) printf("是回文串\n");

    else printf("不是回文串\n");
    return 0;
}

//
// Created by 冲哥 on 2020/12/29.
//
#include <stdio.h>

struct student {
    int num;//学号
    char *name;//姓名
    char sex;//性别
    int age;//年龄

} stu[5] = {{1001, "张三",    'F', 18},
            {1002, "李四",  'M', 28},
            {1003, "王五",  'F', 34},
            {1004, "赵六", 'F', 25},
            {1005, "前七", 'M', 19}};

int main() {
    int i;
    struct student *ps;
    printf("Num \tName\t\t\tSex\tAge\t\n");

    //用指针变量输出结构体数组元素。
    for (ps = stu; ps < stu + 5; ps++)
        printf("%d\t%-10s\t\t%c\t%d\t\n", ps->num, ps->name, ps->sex, ps->age);
    printf("************************************\n");
    //用数组下标法输出结构体数组元素学号和年龄。
    for (i = 0; i < 5; i++)

        printf("%d\t%d\t\n", stu[i].num, stu[i].age);
    return 0;
}