实验四
task1-1
#include<stdio.h> #define N 4 int main(){ int a[N]={2,0,2,3}; char b[N]={'2','0','2','3'}; int i; printf("sizeof(int)=%d\n",sizeof(int)); printf("sizeof(char)=%d\n",sizeof(char)); printf("\n"); for(i=0;i<N;++i) printf("%p:%c\n",&a[i],a[i]); printf("\n"); for(i=0;i<N;++i) printf("%p:%c\n",&b[i],b[i]); printf("\n"); printf("a=%p\n",a); printf("b=%p\n",b); return 0; }
1、int型数组a在内存中是连续存放的,每个元素占四个字节。
2、int型数组b在内存中是连续存放的,每个元素占一个字节。
3、一样 一样
task1-2
int main(){ int a[N][M]={{1,2,3},{4,5,6}}; char b[N][M]={{'1','2','3'},{'4','5','6'}}; int i,j; for(i=0;i<N;++i) for(j=0;j < M;++j) printf("%p:%c\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"); 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]); printf("\n"); return 0; }
1、是,4
2、一样
3、是,1
4、一样
5、a=a[0],a[1]比a[0]多占三个字符的空间,b=b[0],b[1]比b[0]多占三个字符的空间
task2
void test2(); int main(){ printf("测试1:用两个一维数组,实现两个字符串的交换\n"); test1(); printf("\n测试:用二维数组,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); }
task3-1
#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 number=0; for(i=0;x[i]!='\0';i++){ if(x[i]==' ') word_flag=0; else if(word_flag==0){ word_flag=1; number++; } } return number; }
task3-2
#include<stdio.h> #define N 1000 int count(char x[]); 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 ; }
task4
#include<stdio.h> #define N 5 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("\n录入%d个分数:\n",N); input(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; } //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"); } //计算整型数组x中n个元素的均值,并返回 double average(int x[],int n){ double sum=0; double ave; for(int i=0;i<n;++i){ sum+=x[i]; } ave=sum/n; return ave; } //对整型数组x中的n个元素降序排序 void bubble_sort(int x[],int n){ int i,j,k; for(i=0;i<n-1;i++){ for(j=0;j<n-1-i;j++) if(x[j]>x[j+1]){ k=x[j]; x[j]=x[j+1]; x[j+1]=k; } } }
task5
#include<stdio.h> #define N 100 void dec2n(int x,int n); int main(){ int x; printf("输入一个十进制整数:"); while(scanf("%d",&x)!=EOF){ dec2n(x,2); dec2n(x,8); dec2n(x,16); printf("\n输入一个十进制整数:"); } return 0; } void dec2n(int x,int n){ int i,j,m,num=0; char a[N]; char b[N]; char c[N]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'}; for(i=0;i<N;i++){ m=x%n; x=(x-m)/n; a[i]=c[m]; num++; if(x==0) break; } for(j=0;j<=num;j++){ b[j]=a[i-j]; printf("%c",b[j]); } printf("\n"); }
task6
#include <stdio.h> #define N 100 #define M 4 void output(int x[][N], int n); // 函数声明 void rotate_to_right(int x[][N], int n); // 函数声明 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; } // 函数定义 // 功能: 输出一个n*n的矩阵x 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 a[i]; for(i=0;i<n;++i){ a[i]=x[i][n-1]; } for(i=0;i<n;++i){ for(j=n-1;j>=0;j--){ x[i][j]=x[i][j-1]; }} for(i=0;i<n;++i){ x[i][0]=a[i]; } }
task7-1
#include<stdio.h> #define N 80 void replace(char x[],char old_char, char new_char); int main(){ char text[N]="c programming is difficultor not, it is a question."; printf("原始文本:\n"); printf("%s\n",text); replace(text,'i','*'); printf("处理后文本:\n"); printf("%s\n",text); return 0; } void replace(char x[],char old_char, char new_char){ int i; for (i = 0; x[i] != '\0'; ++i) // 思考: '\0'是什么,为什么能作为循环结束条件 if (x[i] == old_char) x[i] = new_char; }
task7-2
#include <stdio.h> #define N 80 int main() { char str[N], ch; int i; printf("输入字符串: "); gets(str); printf("输入一个字符: "); ch = getchar(); printf("截断处理......"); i = 0; while (str[i] != '\0') { if (str[i] == ch){ for(;i<=N-1;i++) str[i]='\0'; } i++; } printf("\n截断处理后字符串: %s\n", str); return 0; }
1、将old_char 替换为new_char
2、\0 是NULL 判定字符数组结束的标识
task8
#include <stdio.h> #include <string.h> #define N 5 #define M 20 void bubble_sort(char str[][M], int n); // 函数声明 int main() { char name[][M] = {"Bob", "Bill", "Joseph", "Taylor", "George"}; int i; printf("输出初始名单:\n"); for (i = 0; i < N; i++) printf("%s\n", name[i]); 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"); for (i = 0; i < N; i++) printf("%s\n", name[i]); return 0; } // 函数定义 // 功能:使用冒泡排序算法对二维数组str中的n个字符串按字典序排序 void bubble_sort(char str[][M], int n){ int i,j; char temp[M]; for(i=0;i<n-1;i++){ for(j=0;j<n-1;j++){ if(strcmp(str[j],str[j+1])>0){ strcpy(temp,str[j+1]); strcpy(str[j+1],str[j]); strcpy(str[j],temp); } } } }