demo_3_21

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <stdlib.h>
int main()
{
    int array[100];
    //向array数组中填充1~100所有数据
    for (int i = 0; i < 100; i++)
    {
        array[i] = i + 1;
    }
    //1不是素数，将1划掉-->使用0进行填充
    array[0] = 0;
    for (int i = 1; i < 100; ++i)
    {
        if (0 == array[i]) continue;
        //现在需要使用array[i]去模其之后所有数据
        for (int j = i + 1; j < 100; ++j)
        {
            if (0!=array[j]&&array[j] % array[i]==0)
            {
                array[j] = 0;
            }
        }
    }
    //输出所有素数
    for (int i = 0; i < 100; ++i)
    {
        if (0 != array[i])
        {
            printf("%d ", array[i]);
        }
    }
    printf("\n");
    system("pause");
    return 0;
}


int main()
{
    int i, j;
    int array[10] = { 2, 8, 3, 9, 5, 7, 1, 4, 0, 6 };
    int maxPos=0,temp;
    int size_arr = sizeof(array) / sizeof(array[0]);
    for (i = 0; i < size_arr; ++i)
    {
        printf("%d ", array[i]);
    }
    printf("\n");
    //设置循环的趟数
    for (i = 0; i < size_arr; ++i)
    {
        //具体选择的方式
        //用选择法来排序
        maxPos = 0;
        for (j = 1; j < size_arr-i; ++j)
        {
            if (array[j]>array[maxPos])
            {
                maxPos = j;
            }
        }
        //判断，已经找到元素最大值，就不需要交换了
        if (maxPos != size_arr - i - 1)
        {
            //将最大值的空间与当前值的空间交换
            temp = array[maxPos];
            array[maxPos] = array[size_arr - i - 1];
            array[size_arr - i - 1] = temp;
        }
    }
    for (i = 0; i < size_arr; ++i)
    {
        printf("%d ", array[i]);
    }
    printf("\n");
    system("pause");
    return 0;
}


int main()
{
    int array[3][3];
    int i, j;
    int array_left = 0, array_right = 0;
    //接受矩阵中的数据
    for (i = 0; i < 3; ++i)
    {
        for (j = 0; j < 3; ++j)
        {
            scanf("%d", &array[i][j]);
        }
    }
    //求左上角到右下角对角线元素之和
    //行下标与列下标是相等的
    for (i = 0; i < 3; ++i)
    {
        array_left += array[i][i];
    }
    //右上角到左下标对角线元素之和
    for (i = 0, j = 2; i < 3; i++)
    {
        array_right += array[i][j];
    }
    printf("求左上角到右下角对角线元素之和 %d\n", array_left);
    printf("右上角到左下标对角线元素之和 %d\n", array_right);
    system("pause");
    return 0;
}


int main()
{
    int key = 0;
    int end = 8;
    int array[10] = { 0, 1, 2, 3, 4, 6, 7, 8, 9 };
    printf("请输入要插入的元素:>");
    scanf("%d", &key);
    printf("原数组中的元素:0, 1, 2, 3, 4, 6, 7, 8, 9\n");
    //找待插入元素在数组中的位置--从后往前进行查找
    //注意：如果待插入元素比较数组中任何一个元素小
    //因此end应该保证大于等于0，防止越界情况
    while (key < array[end] && end >= 0)
    {
        array[end + 1] = array[end];
        end--;
    }
    //插入元素
    array[end + 1] = key;
    for (int i = 0; i < 10; ++i)
    {
        printf("%d ", array[i]);
    }
    printf("\n");
    system("pause");
    return 0;
}


int main()
{
    int array[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    printf("逆序之前数组元素序列为:");
    for (int i = 0; i < sizeof(array)/sizeof(array[0]); ++i)
    {
        printf("%d ", array[i]);
    }
    //从左侧找一个数据，从右侧找一个数据
    int begin=0, end=sizeof(array)/sizeof(array[0])-1;
    //定义临时变量进行交换
    int temp = 0;
    while (begin < end)
    {
        temp = array[begin];
        array[begin] = array[end];
        array[end] = temp;
        begin++;
        end--;
    }
    printf("\n");
    //打印输出
    printf("逆序之后数组元素序列为:");
    for (int i = 0; i < sizeof(array)/sizeof(array[0]); ++i)
    {
        printf("%d ", array[i]);
    }
    printf("\n");
    system("pause");
    return 0;
}


int main()
{
    int i, j;
    //保存杨辉三角形中的数据
    int array[10][10];
    for (i = 0; i < 10; ++i)
    {
        //每一行进行赋值
        for (j = 0; j <= i; ++j)
        {
            if (j == 0 || i == j)
            {
                array[i][j] = 1;
            }
            else{
                //其他位置
                array[i][j] = array[i - 1][j] + array[i - 1][j - 1];
            }
        }
    }
    //一行一行的进行打印
    for (i = 0; i < 10; ++i)
    {
        for (j = 0; j <= i; ++j)
        {
            printf("%6d ", array[i][j]);
        }
        printf("\n");
    }
    system("pause");
    return 0;
}


//奇魔方阵
int main()
{
    int array[100][100] = { 0 };
    int N;
    int row = 0, col = 0;
    int prevRow = 0, prevCol = 0;
    int i,j;
    while (1)
    {
        printf("请输入奇魔方阵的阶数，阶数是3-100之内的奇数：");
        scanf("%d", &N);
        if (0 != N % 2 && (N >= 3 && N < 100))
        {
            break;
        }
    }
    //放置1：第0行中间的位置
    col = N / 2;
    array[row][col] = 1;
    //对于剩余的N^2-1个元素，按照以下规则来存放
    for (i = 2; i <= N*N; ++i)
    {
        //下一个元素存放在当前元素上一行下一列
        row--;
        col++;
        if (row < 0)
        {
            row = N - 1;
        }
        if (col >= N)
        {
            col = 0;
        }
        if (0 != array[row][col])
        {
            //row,col该位置已经有元素--前一个元素当前列的下一行
            row = prevRow + 1;
            col = prevCol;
        }
        array[row][col] = i;
        prevRow = row;
        prevCol = col;
    }
    //将魔方阵输出
    for (i = 0; i < N; ++i)
    {
        for (j = 0; j < N; ++j)
        {
            printf("%4d", array[i][j]);
        }
        printf("\n");
    }
    system("pause");
    return 0;
}


#define M 3
#define N 4
int main()
{
    int array[M][N];
    int i, j;
    int max, pos=0,flag=0;
    printf("请输入%d行%d列二维数组:\n",M,N);
    for (i = 0; i < M; ++i)
    {
        for (j = 0; j < N; ++j)
        {
            scanf("%d", &array[i][j]);
        }
    }
    //找鞍点
    for (i = 0; i < M; ++i)
    {
        //找该行最大的元素
        max = array[i][0];
        for (j = 0; j < N; ++j)
        {
            if (array[i][j]>max)
            {
                max = array[i][i];
                pos = j;
            }
        }
        //确认该元素是否为该列上最大的元素
        //列号不变，行号增加
        for (j = 0; j < M; ++j)
        {
            if (array[j][pos] < max)
            {
                //不是鞍点，就直接跳出循环
                break;
            }
        }
        //如果在pos列没有发现比max小的元素，说明max是pos是列上最小的元素
        if (j == M)
        {
            //鞍点找到了
            printf("鞍点为：%d行，%d列%d", i, pos, array[i][pos]);
            flag = 1;
            break;
        }
    }
    if (flag != 1)
    {
        printf("没有鞍点\n");
    }
    system("pause");
    return 0;
}


int main()
{
    int left=0, right=0, mid;
    int key;
    int array[] = { 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };
    //区间采用左闭右开
    left = 0;
    right = sizeof(array) / sizeof(array[0]);
    printf("请输入待查找的数据:>");
    scanf("%d", &key);
    while (left < right)
    {
        //找中间位置
        //该求中间位置的方式可能为溢出
        //mid = (left + right) / 2;
        mid = left + ((right - left) >> 1);
        //与中间位置数据进行比较
        //相等-->找到了
        //大于-->中间位置数据
        //小于-->中间位置数据
        if (key == array[mid])
        {
            printf("找到该元素，其在数组中的下标为:%d\n", mid);
            break;
        }
        else if (key < array[mid])
        {
            left = mid + 1;
        }
        else {
            right = mid;
        }
    }
    if (left == right)
    {
        printf("抱歉，没有这个数\n");
    }
    system("pause");
    return 0;
}

int main()
{
    int left = 0, right = 0, mid;
    int key;
    int array[] = { 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 };
    //区间采用左闭右闭
    left = 0;
    right = sizeof(array) / sizeof(array[0])-1;
    printf("请输入待查找的数据:>");
    scanf("%d", &key);
    while (left <= right)
    {
        //找中间位置
        //该求中间位置的方式可能为溢出
        //mid = (left + right) / 2;
        mid = left + ((right - left) >> 1);
        //与中间位置数据进行比较
        //相等-->找到了
        //大于-->中间位置数据
        //小于-->中间位置数据
        if (key == array[mid])
        {
            printf("找到该元素，其在数组中的下标为:%d\n", mid);
            break;
        }
        else if (key < array[mid])
        {
            left = mid + 1;
        }
        else {
            right = mid-1;
        }
    }
    if (left > right)
    {
        printf("抱歉，没有这个数\n");
    }
    system("pause");
    return 0;
}


int main()
{
    //先输入三行文本
    //不能使用scanf接收三行文本
    //scanf 遇到空格、回车就不往后输入了
    char sz[3][80] = { 0 };
    int i ,j;
    int upper = 0, lower = 0, digit = 0, space = 0, other = 0;
    for (i = 0; i < 3; ++i)
    {
        gets(sz[i]);
    }
    //统计
    for (i = 0; i < 3; ++i)
    {
        //只需要在该行中统计到\0的位置
        for (j = 0; sz[i][j] != '\0'; ++j)
        {
            //A-Z
            if (sz[i][j] >= 'A'&&sz[i][j] <= 'Z')
            {
                upper++;
            }
            //a-z
            else if (sz[i][j] >= 'a'&&sz[i][j] <= 'z')
            {
                lower++;
            }
            //0-9
            else if (sz[i][j] >= '0'&&sz[i][j] <= '9')
            {
                digit++;
            }
            //' '
            else if (sz[i][j] == ' ')
            {
                space++;
            }
            //其他字符
            else {
                other++;
            }
        }
    }
    printf("大写字母有：%d\n", upper);
    printf("小写字母有：%d\n", lower);
    printf("数字字符有：%d\n", digit);
    printf("空格字符有：%d\n", space);
    printf("其他字符有：%d\n", other);
    system("pause");
    return 0;
}


int main()
{
    int i ,j;
    for (i = 0; i < 5; ++i)
    {
        //前面的空格
        for (j = 0; j < 2 * i; ++j)
        {
            printf(" ");
            printf("* * * * *");
        }
        //后面的星号
        
        printf("\n");
    }
    
    system("pause");
    return 0;
}


int main()
{
    //获取暗文
    //假设暗文长度为100个字符
    char sz[100];
    gets(sz);
    //解码--'A'+(26-(ch-'A')-1)
    //只对字母进行解码
    for (int i = 0; sz[i]!='\0'; ++i)
    {
        //'A'-'Z'
        if (sz[i] >= 'A'&&sz[i] <= 'Z')
        {
            sz[i] = 'A' + (26 - (sz[i] - 'A') - 1);
        }
        if (sz[i] >= 'z'&&sz[i] <= 'z')
        {
            sz[i] = 'a' + (26 - (sz[i] - 'a') - 1);
        }
    }
    printf("解码为:%s\n", sz);
    system("pause");
    return 0;
}


int main()
{
    char dst[100] = { 0 };
    char src[50] = { 0 };
    int i = 0,j=0;
    printf("请输入目标字符串:>");
    gets(dst);
    printf("请输入源字符串:>");
    gets(src);
    //找到s1的末尾
    while (dst[i]!='\0')
    {
        i++;
    }
    //将src中的每个字符逐个拷贝到dst中
    while (src[j] != '\0')
    {
        dst[i] = src[j];
        i++;
        j++;
    }
    //注意：需要拷贝'\0'
    dst[i] = '\0';
    printf("%s\n", dst);
    system("pause");
    return 0;
}


int main()
{
    char s1[100] = { 0 };
    char s2[100] = { 0 };
    int ret = 0, i = 0;
    printf("请输入s1:>");
    gets(s1);
    printf("请输入s2:>");
    gets(s2);
    //字符串比较规则：只需要将两个字符串逐个进行比较，减法
    //while ((ret = (s1[i] - s2[i]) != 0) && s1[i] && s2[i])
    do
    {
        ret = s1[i] - s2[i];
        if (0 != ret)
        {
            break;
        }
        i++;
    } while (s1[0] != '\0'&&s2[0] != '\0');
    printf("%d\n", ret);
    system("pause");
    return 0;
}



int main()
{
    char s1[100] = { 0 };
    char s2[100] = { 0 };
    int i = 0;
    printf("请输入要拷贝的字符串:>");
    gets(s2);
    //拷贝方式：将s2中的每个字符逐个拷贝到s1
    //while (s1[i] = s2[i++])
    //先将s2中的元素拷贝到s1[i]
    //s1[i]中的字符作为判断条件
    //i++考虑到后面的字符
    while (s2[i] != '\0')
    {
        s1[i] = s2[i];
        i++;
    }
    //把\0赋给s1
    s1[i] = '\0';
    printf("拷贝后的字符串s1为:%s\n", s1);
    system("pause");
    return 0;
}


int main()
{
    char a = 'H';
    a = (a >= 'A'&&a <= 'Z') ? (a - 'A' + 'a') : a;
    printf("%c\n", a);
    
    system("pause");
    return 0;
}

int f(int x)
{
    return x = x + 1;
}
int main()
{
    int a, b = 0;
    for (a = 0; a < 3; a++)
    {
        b = b + f(a);
        putchar('A' + b);
    }
    system("pause");
    return 0;
}

int main()
{
    int a[] = { 10, 20, 30, 40 }, *p = a, i;
    for (i = 0; i <= 3; i++)
    {
        a[i] = *p;
        p++;
    }
    printf("%d\n", a[2]);
    system("pause");
    return 0;
}

#define N 3
void fun(int a[][N], int b[])
{
    int i, j;
    for (i = 0; i < N; i++)
    {
        b[i] = a[i][0];
        for (j = 1; j < N; j++)
        {
            if (b[i] < a[i][j]) b[i] = a[i][j];
        }
    }
}
int main()
{
    int x[N][N] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }, y[N], i;
    fun(x, y);
    for (i = 0; i < N; i++)
    {
        printf("%d,", y[i]);
    }
    printf("\n");
    system("pause");
    return 0;
}

int main()
{
    char a[10] = "abc", b[10] = "012", c[10] = "xyz";
    strcpy(a + 1, b + 2);
    puts(strcat(a, c + 1));
    system("pause");
    return 0;
}

int main()
{
    char *s = "12134";
    int k = 0, a = 0;
    while (s[k + 1] != '\0')
    {
        k++;
        if (k % 2 == 0)
        {
            a = a + (s[k] - '0' + 1); continue;

        }
        a = a + (s[k] - '0');
    }
    printf("k=%d a=%d\n", k, a);
    system("pause");
    return 0;
}

int main()
{
    char a[5][10] = { "one", "two", "three", "four", "five" };
    int i, j;
    char t;
    for (i = 0; i < 4; i++)
    {
        for (j = i + 1; j < 5; j++)
        {
            if (a[i][0]>a[j][0])
            {
                t = a[i][0];
                a[i][0] = a[i][0];
                a[i][0] = t;
            }
            puts(a[1]);
        }
    }
    
    system("pause");
    return 0;
}

int a = 1, b = 2;
void fun1(int a, int b)
{
    printf("%d %d", a, b);
}
void fun2()
{
    a = 3, b = 4;
}
int main()
{
    fun1(5, 6);
    fun2();
    printf("%d %d\n", a, b);
    system("pause");
    return 0;
}

void func(int n)
{
    static int num = 1;
    num = num + n;
    printf("%d ", num);
}
int main()
{
    func(3);
    func(4);
    printf("\n");
    system("pause");
    return 0;
}

void fun(int *p1, int *p2, int *s)
{
    s = (int *)malloc(sizeof(int));
    *s = *p1 + *p2;
    free(s);
}
int main()
{
    int a = 1, b = 40, *q = &a;
    fun(&a, &b, q);
    printf("%d\n", *q);
    system("pause");
    return 0;
}

int main()
{
    FILE *fp;
    int i, s[6] = { 1, 2, 3, 4, 5, 6 };
    fp = fopen("d2.dat", "w+");
    for (i = 0; i < 6; i++)
    {
        fprintf(fp, "%d\n", s[i]);
    }
    rewind(fp);
    for (i = 0; i < 6; i++)
    {
        fscanf(fp, "%d", &s[5 - i]);
    }
    fclose(fp);
    for (i = 0; i < 6; i++)
    {
        printf("%d,", s[i]);
    }
    system("pause");
    return 0;
}