如何在C

Question

  

案例3是问题区域，整数数组正在运行，它很好，但是＆＃34;第一个＆＃34;和＆＃34;最后＆＃34;字符串数组根本不起作用。我不知道如何解决它。

     

我必须只使用stdio.h和stdlib.h库。＆＃34; first＆＃34;和＆＃34;最后＆＃34;是2d char指针，我喜欢20个元素，最多30个字符。添加和编辑都很好，但是＆＃34;首先[temp] =第一个[temp + 1];＆ ＃34;当我尝试＆＃34; strcpy（first [temp]，first [temp + 1]）;＆＃34;没有编译器错误。

     

最终使用strcpy。当我想删除字符串时保持不变，整数取值为0

int main(){

    printf("Welcome to address book ! \n ");
    printf("--------------------------------------------------------\n");
    int a=0;
    int temp=0;
    char* first[20][30];
    char* last[20][30];
    int n[20];
    int g=0;

    while(a<=1000){
        int b=0;
        printf("What do you want? \n");
        printf("1-New ID\n2-Edit ID\n3-Delete ID\n4-List All ID's\n5-Close the Program\n");
        printf("--------------------------------------------------------\n");
        scanf("%d",&b);

        switch(b){
        case 1:
           printf("Enter Fist Name \n");
           scanf("%s",&first[g]);
           printf("Enter Last Name\n");
           scanf("%s",&last[g]);
           printf("Enter Student Number\n");
           scanf("%d",&n[g]);
           g++;
        a++;
        continue;
        case 2:
            printf("Which user you want to change ?\n");
            printf("user sequence :");
            scanf("%d",&temp);
            temp=temp-1;
            printf("Listed First Name : %s\n",first[temp]);
            printf("New First Name : ");
            scanf("%s",&first[temp]);

            printf("Listed Last Name : %s\n",last[temp]);
            printf("New Last Name : ");
            scanf("%s",&last[temp]);

            printf("Listed Number : %d\n",n[temp]);
            printf("New Listed Number : ");
            scanf("%d",&n[temp]);

            temp=0;
         a++;
        continue;
        case 3:
            printf("which user do you want to delete :");
            scanf("%d",&temp);
            if(temp+1<=g){
             //   first[temp]=first[temp+1];
            //  last[temp]=last[temp+1];
                n[temp]=n[temp+1];
            }
            else
                printf("unavailable");
        a++;
        continue;
        case 4:
           printf("--------------------------------------------------------\n");
           int u;
           for(u=0;u<g;u++){
            printf(">%d.user.  ",u+1);
            printf("%d\t",n[u]);
            printf("%s\t",first[u]);
            printf("%s\n",last[u]);
           }
           printf("\n--------------------------------------------------------\n");
          a++;
          continue;
        case 5:
            printf("\nThank you for the use this program !\n ");
        temp= 1000-a;
        a= a+temp;
        a++;
        continue;
        }
    }
    return 0;}