实验4

1.1

#include <stdio.h>
#define N 4

void test1() {
    int a[N] = {1, 9, 8, 4};          
    int i;
    printf("sizeof(a) = %d\n", sizeof(a));
    for (i = 0; i < N; ++i)
        printf("%p: %d\n", &a[i], a[i]);
    printf("a = %p\n", a); 
}

void test2() {        
    char b[N] = {'1', '9', '8', '4'}; 
    int i;
    printf("sizeof(b) = %d\n", sizeof(b));
    for (i = 0; i < N; ++i)
        printf("%p: %c\n", &b[i], b[i]);
    printf("b = %p\n", b); 
}

int main() {
    printf("测试1: int类型一维数组\n");
    test1();
    printf("\n测试2: char类型一维数组\n");
    test2();
    return 0;
}

a：连续 4 一样

b：连续 1 一样

1.2

#include <stdio.h>
#define N 2
#define M 4

void test1() {
    int a[N][M] = {{1, 9, 8, 4}, {2, 0, 4, 9}};
    int i, j;
    printf("sizeof(a) = %d\n", sizeof(a));
    for (i = 0; i < N; ++i)
        for (j = 0; j < M; ++j)
            printf("%p: %d\n", &a[i][j], a[i][j]);
    printf("\n");
    printf("a = %p\n", a);
    printf("a[0] = %p\n", a[0]);
    printf("a[1] = %p\n", a[1]);
    printf("\n");
}

void test2() {
    char b[N][M] = {{'1', '9', '8', '4'}, {'2', '0', '4', '9'}};
    int i, j;
    printf("sizeof(b) = %d\n", sizeof(b));
    for (i = 0; i < N; ++i)
        for (j = 0; j < M; ++j)
            printf("%p: %c\n", &b[i][j], b[i][j]);
    printf("\n");
    printf("b = %p\n", b);
    printf("b[0] = %p\n", b[0]);
    printf("b[1] = %p\n", b[1]);
}

int main() {
    printf("测试1: int型两维数组");
    test1();

    printf("\n测试2: char型两维数组");
    test2();

    return 0;
}

连续 4 一样

连续 1 一样

2

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

#define N 80

void swap_str(char s1[], char s2[]);
void test1();
void test2();

int main() {
    printf("测试1: 用两个一维char数组，实现两个字符串交换\n");
    test1();

    printf("\n测试2: 用二维char数组，实现两个字符串交换\n");
    test2();

    return 0;
}

void test1() {
    char views1[N] = "hey, C, I hate u.";
    char views2[N] = "hey, C, I love u.";

    printf("交换前: \n");
    puts(views1);
    puts(views2);

    swap_str(views1, views2);

    printf("交换后: \n");
    puts(views1);
    puts(views2);
}

void test2() {
    char views[2][N] = {"hey, C, I hate u.", 
                        "hey, C, I love u."};

    printf("交换前: \n");
    puts(views[0]);
    puts(views[1]);

    swap_str(views[0], views[1]);

    printf("交换后: \n");
    puts(views[0]);
    puts(views[1]);
}

void swap_str(char s1[N], char s2[N]) {
    char tmp[N];

    strcpy(tmp, s1);
    strcpy(s1, s2);
    strcpy(s2, tmp);
}

test1是一维数组，直接用，test2是二维数组，views[i]相当于行，二者有所不同

3.1

#include <stdio.h>

#define N 80

int count(char x[]);

int main() {
    char words[N+1];
    int n;

    while(gets(words) != NULL) {
        n = count(words);
        printf("单词数: %d\n\n", n);
    }

    return 0;
}

int count(char x[]) {
    int i;
    int word_flag = 0;  
    int cnt = 0; 

    for(i = 0; x[i] != '\0'; i++) {
        if(x[i] == ' ')
            word_flag = 0;
        else if(word_flag == 0) {
            word_flag = 1;
           cnt++;
        }
    }

    return cnt;
}

3.2

#include <stdio.h>
#define N 1000

int main() {
    char line[N];
    int word_len;
    int max_len;
    int end;
    int i;

    while(gets(line) != NULL) {
        word_len = 0;
        max_len = 0;
        end = 0;

        i = 0;
        while(1) {
            while(line[i] == ' ') {
                word_len = 0; 
                i++;
            }
            while(line[i] != '\0' && line[i] != ' ') {
                word_len++;
                i++;
            }
            if(max_len < word_len) {
                max_len = word_len;
                end = i;
            }
            if(line[i] == '\0')
                break;
        }
        printf("最长单词: ");
        for(i = end - max_len; i < end; ++i)
            printf("%c", line[i]);
        printf("\n\n");
    }

    return 0;
}

 

4

#include <stdio.h>
#define N 100
void dec_to_n(int x,int n);
int main() {
int x;
printf("输入一个十进制整数: ");
while(scanf("%d", &x) != EOF) {
dec_to_n(x, 2);
dec_to_n(x, 8);
dec_to_n(x, 16);
printf("\n输入一个十进制整数: ");
}
return 0;
}
void dec_to_n(int x,int n){
    char ans[N];
    char map[17]="0123456789ABCDEF";
    int d,r; 
    int cnt,i;
    cnt=0;
    while(1){
        d=x/n;
        r=x%n;
        ans[cnt++]=map[r];
        if(d == 0)
        break;
        x=d;
    }
    for(i=cnt-1;i>=0;--i)
    printf("%c",ans[i]);
    printf("\n");
}

 5

#include <stdio.h>
#define N 5

// 函数声明 
void input(int x[], int n);
void output(int x[], int n);
double average(int x[], int n);
void bubble_sort(int x[], int n);

int main() {
    int scores[N];
    double ave;
    
    printf("录入%d个分数:\n", N);
    input(scores, N);
    
    printf("\n输出课程分数: \n");
    output(scores, N);
    
    printf("\n课程分数处理: 计算均分、排序...\n");
    ave = average(scores, N);
    bubble_sort(scores, N);
    
    printf("\n输出课程均分: %.2f\n", ave);
    printf("\n输出课程分数(高->低):\n");
    output(scores, N);
    
    return 0;
}

// 函数定义
// 输入n个整数保存到整型数组x中 
void input(int x[], int n) {
    int i;
    
    for(i = 0; i < n; ++i)
        scanf("%d", &x[i]); 
}

// 输出整型数组x中n个元素 
void output(int x[], int n) {
    int i;
    
    for(i = 0; i < n; ++i)
        printf("%d ", x[i]);
    printf("\n");
}
double average(int x[], int n){
    int i;
    double ave,s;
    for(i=0;i<n;++i)
       s +=x[i];
    ave=s/n;
    return ave;
} 
void bubble_sort(int x[], int n){
    int i,j,t;
    for(i=0;i<n-1;i++){
        for(j=0;j<n-i-1;j++){
            if(x[j]<x[j+1]){
                t=x[j];
                x[j]=x[j+1];
                x[j+1]=t;
            }
        }
    }
}

 

 

6

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

#define N 5
#define M 20

// 函数声明
void output(char str[][M], int n);
void bubble_sort(char str[][M], int n);

int main() {
    char name[][M] = {"Bob", "Bill", "Joseph", "Taylor", "George"};
    int i;

    printf("输出初始名单:\n");
    output(name, N);

    printf("\n排序中...\n");
    bubble_sort(name, N);  // 函数调用 

    printf("\n按字典序输出名单:\n");
    output(name, N);

    return 0;
}

// 函数定义
// 功能：按行输出二维数组中的字符串
void output(char str[][M], int n) {
    int i;

    for(i = 0; i < n; ++i)
        printf("%s\n", str[i]);
}
void bubble_sort(char str[][M], int n){
    int i,j;
    char t[100];
    for(i=0;i<n;++i){
      for(j=0;j<n-1-i;++j){
          if(strcmp(str[j],str[j+1])>0){
             strcpy(t,str[j]);
             strcpy(str[j],str[j+1]);
             strcpy(str[j+1],t);
          }
            
      }
    }
} 

7

#include<stdio.h>
#define N 105

int is_repeated(char x[]);
int main(){
    char num[N];
    while(scanf("%s",num)!=EOF){
        if(is_repeated(num))
           printf("YES\n");
        else
           printf("NO\n");
    }
    return 0;
}
int is_repeated(char x[]){
    int cnt[10] = {0};
    int i,j;
    for(i=0;x[i]!='\0';++i){
       j=x[i]-'0';
       cnt[j]++;
       if(cnt[j]>1)
         return 1;
}
    return 0;
}

 

 

8

#include <stdio.h>
#define N 100
#define M 4


void output(int x[][N], int n);          
void rotate_to_right(int x[][N], int n); 


int main() {
    int t[][N] = {{21, 12, 13, 24},
                  {25, 16, 47, 38},
                  {29, 11, 32, 54},
                  {42, 21, 33, 10}};

    printf("原始矩阵:\n");
    output(t, M); 

    rotate_to_right(t, M); 

    printf("变换后矩阵:\n");
    output(t, M); 

    return 0;
}

void output(int x[][N], int n) {
    int i, j;

    for (i = 0; i < n; ++i) {
        for (j = 0; j < n; ++j)
            printf("%4d", x[i][j]);

        printf("\n");
    }
}
void rotate_to_right(int x[][N], int n){
    int i,j;
    int t[N];
    for(i=0;i<n;i++)
       t[i]=x[i][n-1];
    for(i=0;i<n;i++){
        for(j=n-1;j>=0;j--){
           x[i][j+1]=x[i][j];
        }
    for(i=0;i<n;i++)
       x[i][0]=t[i];
    }

}