实验六

#include <stdio.h>
#define N 4
 
int main()
{
    int x[N] = {1, 9, 8, 4};
    int i;
    int *p;
 
    for(i=0; i<N; ++i)
        printf("%d", x[i]);
    printf("\n");
 
    for(p=x; p<x+N; ++p)
        printf("%d", *p);
    printf("\n");
 
    p = x;
    for(i=0; i<N; ++i)
        printf("%d", *(p+i));
    printf("\n");
 
    p = x;
    for(i=0; i<N; ++i)
        printf("%d", p[i]);
    printf("\n");
 
    return 0;
}

#include <stdio.h>
#define N 4
 
int main()
{
    char x[N] = {'1', '9', '8', '4'};
    int i;
    char *p;
 
    for(i=0; i<N; ++i)
        printf("%c", x[i]);
    printf("\n");
 
    for(p=x; p<x+N; ++p)
        printf("%c", *p);
    printf("\n");
 
    p = x;
    for(i=0; i<N; ++i)
        printf("%c", *(p+i));
    printf("\n");
 
    p = x;
    for(i=0; i<N; ++i)
        printf("%c", p[i]);
    printf("\n");
 
    return 0;
}

2004

2001

字符类型不同，存储类型不同

#include <stdio.h>
 
int main()
{
    int x[2][4] = { {1,9,8,4}, {2,0,2,2}} ;
    int i, j;
    int *p;
    int (*q)[4];
 
    for(i=0; i<2; ++i)
    {
        for(j=0; j<4; ++j)
            printf("%d", x[i][j]);
        printf("\n");
     }
 
    for(p = &x[0][0], i = 0; p < &x[0][0] + 8; ++p, ++i)
    {
        printf("%d", *p);
        if( (i+1)%4 == 0)
            printf("\n");
    }
 
    for(q=x; q<x+2; ++q)
    {
        for(j=0; j<4; ++j)
            printf("%d", *(*q+j));
        printf("\n");
    }
 
    return 0;
}

#include <stdio.h>
 
int main()
{
    char x[2][4] = { {'1', '9', '8', '4'}, {'2', '0', '2', '2'} };
    int i, j;
    char *p;
    char (*q)[4];
 
    for(i=0; i<2; ++i)
    {
        for(j=0; j<4; ++j)
            printf("%c", x[i][j]);
        printf("\n");
    }
 
    for(p = &x[0][0], i = 0; p < &x[0][0] + 8; ++p, ++i)
    {
        printf("%c", *p);
        if( (i+1)%4 == 0)
            printf("\n");
    }
 
    for(q=x; q<x+2; ++q)
    {
        for(j=0; j<4; ++j)
            printf("%c", *(*q+j));
        printf("\n");
    }
 
    return 0;
}

#include <stdio.h>
#include <string.h>
#define N 80
int main()
{
    char s1[] = "C, I love u.";
    char s2[] = "C, I hate u.";
    char tmp[N];

    printf("sizeof(s1) vs. strlen(s1):\n");
    printf("sizeof(s1)=%d\n", sizeof(s1));
    printf("strlen(s1)=%d\n", strlen(s1));

    printf("\nbefore swap: \n");
    printf("s1: %s\n", s1);
    printf("s2: %s\n", s2);

    printf("\nswapping...\n");
    strcpy(tmp, s1);
    strcpy(s1, s2);
    strcpy(s2, tmp);

    printf("\nafter swap:\n");
    printf("s1:%s\n", s1);
    printf("s2:%s\n", s2);

    return 0;
}

#include <stdio.h>
#include <string.h>
#define N 80
int main()
{
    char* s1 = "C, I love u.";
    char* s2 = "C, I hate u.";
    char* tmp;

    printf("sizeof(s1) vs. strlen(s1): \n");
    printf("sizeof(s1) = %d\n", sizeof(s1));
    printf("strlen(s1) = %d\n", strlen(s1));

    printf("\nbefore swap: \n");
    printf("s1: %s\n", s1);
    printf("s2: %s\n", s2);

    printf("\nswapping...\n");
    tmp = s1;
    s1 = s2;
    s2 = tmp;

    printf("\nafter swap: \n");
    printf("s1: %s\n", s1);
    printf("s2: %s\n", s2);

    return 0;
}

#include <stdio.h>
#include <string.h>
#define N 5
int check_id(char* str);
int main()
{
    char* pid[N] = { "31010120000721656X",
                    "330106199609203301",
                    "53010220051126571",
                    "510104199211197977",
                    "53010220051126133Y" };
    int i;

    for (i = 0; i < N; i++)
    {
        if (check_id(pid[i]))
            printf("%s\tTrue\n", pid[i]);
        else
            printf("%s\tFalse\n", pid[i]);
    }
    return 0;
}
int check_id(char* str)
{
    int i,flag=1;
    if(strlen(str)==18)
    {
        for(i=0;i<18;i++)
        {
            if((str[i]=='X')||(str[i]>='0'&&str[i]<='9'))
                flag;
            else
                flag=0;
        }
    }
    else
        flag=0;
    return flag;
}

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#define N 80
int is_palindrome(char* s);
int main()
{
    char str[N];
    int flag;
    printf("Enter a string:\n");
    gets_s(str);
    flag = is_palindrome(str);
    if (flag)
        printf("YES\n");
    else
        printf("NO\n");
    return 0;
}
int is_palindrome(char* s)
{
    int i, j = 0;
    char a[N];
    for (i = strlen(s); i >0; i--)
    {
        a[j++] = s[i-1];
    }
    a[j] = '\0';
    if (strcmp(a, s) == 0)
        return 1;
    else
        return 0;
}

#include <stdio.h>
#define N 80
void encoder(char* s); 
void decoder(char* s); 
int main()
{
    char words[N];
    printf("输入英文文本：");
    gets(words);
    printf("编码后的英文文本：");
    encoder(words);
    printf("%s\n", words);
    printf("对编码后的英文文本解码：");
    decoder(words);
    printf("%s\n", words);
    return 0;
}
void encoder(char *s)
{
    char *p;
     p=s;
    while(*p)
    {
    if((*p>='A'&&*p<'Z')||(*p>='a'&&*p<'z'))
    *p+=1;
    else if(*p=='Z'||*p=='z')
    *p-=25;
    p++;
    } 
}
void decoder(char* s)
{
    int i;
    for (i = 0; i <N; i++)
    {
        if ((s[i] >= 'b' && s[i] <= 'z')||s[i]>='B'&&s[i]<='Z')
            s[i]--;
        else if (s[i] == 'a')
            s[i] = 'z';
        else if (s[i] == 'A')
            s[i] = 'Z';
        
    }
}