实验五
任务1:
代码1:
#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"); return 0; }
#include <stdio.h> #define N 4 int main(){ int x[N]={1,9,8,4}; int i; int *p; for(p=x;p<x+N;p++) printf("%d",*p); printf("\n"); return 0; }
截图
代码2:
#include <stdio.h> int main(){ int x[2][4]={{1,9,8,4},{2,0,4,9}}; 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; }
截图
任务2:
代码:
#include <stdio.h> #include <string.h> #define N 80 int main(){ char s1[]="Learning makes me happy"; char s2[]="Learning makes me sleepy"; 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; }
截图
回答:1.24字节,s1的大小,s1的长度。
2.不能,s1表示的是地址,s1【】表示的是数组。
3.发生了交换。
代码2:
#include <stdio.h> #include <string.h> #define N 80 int main(){ char *s1="Learning makes me happy"; char *s2="Learning makes me sleepy"; 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;
截图
回答:1.存放在字符串“Learning makes me happy”的地址,s1所指字符串的大小,s1所指字符串的长度。
2.可以。一个是地址变量,一个是地址常量。
3.地址,没有。
任务3:
代码:
#include <stdio.h> void str_cpy(char *target,const char *source); void str_cat(char *str1, char *str2); int main(){ char s1[80],s2[20]="1984"; str_cpy(s1,s2); puts(s1); str_cat(s1,"Animal Farm"); puts(s1); return 0; } void str_cpy(char *target,const char *source){ while(*target++=*source++) ; } void str_cat(char *str1, char *str2){ while(*str1) str1++; while(*str1++=*str2++); ; }
截图
任务4:
代码:
#include <stdio.h> #define N 80 int func(char *); int main(){ char str[80]; while(gets(str)!=NULL){ if(func(str)) printf("yes\n"); else printf("no\n"); } return 0; } int func(char *str){ char *begin, *end; begin=end=str; while(*end) end++; end--; while(begin<end){ if(*begin!=*end) return 0; else{ begin++; end--; } } return 1; }
截图
任务5:
代码:
#include<stdio.h> #define N 80 void func(char*); int main() { char s[N]; while(scanf("%s",s)!=EOF) { func(s); puts(s); } return 0; } void func(char*str) { int i; char*p1,*p2,*p; p1=str; while(*p1=='*') p1++; p2=str; while(*p2) p2++; p2--; while(*p2=='*') p2--; p=str; i=0; while(p<p1) { str[i]=*p; p++;i++; } while(p<=p2) { if(*p!='*') { str[i]=*p; i++; } p++; } while(*p!='\0') { str[i]=*p; p++; i++; } str[i]='\0'; }
截图
任务6:
代码1:
#include<stdio.h> #include<string.h> void sort(char *name[],int n); int main() { char *course[4]={"CProgram", "C++ObjectOrientedProgram", "OperatingSystem", "DataStructureandAlgorithms"}; int i; sort(course,4); for(i=0;i<4;i++) printf("%s\n",course[i]); return 0; } void sort(char *name[],int n) { int i,j; char *tmp; for(i=0;i<n-1;++i) for(j=0;j<n-1-i;++j) if(strcmp(name[j],name[j+1])>0) { tmp=name[j]; name[j]=name[j+1]; name[j+1]=tmp; } }
截图
代码2:
#include<stdio.h> #include<string.h> void sort(char *name[],int n); int main() { char *course[4]={"CProgram", "C++ObjectOrientedProgram", "OperatingSystem", "DataStructureandAlgorithms"}; int i; sort(course,4); for(i=0;i<4;i++) printf("%s\n",course[i]); return 0; } void sort(char *name[],int n) { int i,j,k; char *tmp; for(i=0;i<n-1;i++) { k=i; for(j=i+1;j<n;j++) if(strcmp(name[j],name[k])<0) k=j; if(k!=i) { tmp=name[i]; name[i]=name[k]; name[k]=tmp; } } }
截图
回答:交换的是指针变量的值。
任务·7:
代码:
#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; for(i=0;*str!='\0';str++,i++) if(*str>'9'&&*str!='X') return 0; if(i<18) return 0; return 1; }
截图:
任务8:
代码:
#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){ for(;*s!='\0';s++){ if('A'<=*s&&'Z'>*s) *s=*s+1; else if(*s=='Z') *s=*s-25; if('a'<=*s&&'z'>*s) *s=*s+1; else if(*s=='z') *s=*s-25; } } void decoder(char *s){ for(;*s!='\0';s++){ if('A'<*s&&'Z'>=*s) *s=*s-1; else if(*s=='A') *s=*s+25; if('a'<*s&&'z'>=*s) *s=*s-1; else if(*s=='a') *s=*s+25; } }
截图: