高手帮我看看，改错，谢谢【c语言吧】

int n,i=0,j,k=0,resu;
char s1[100],s2[100], s[100];
#include "stdio.h"
void main()
{void cpy(char str1[],char str2[]);
char s1[100],s2[100];
/*Print Welcome screen and the main interface*/
printf("\n\n");
printf("a            w eeeeeee   l       ccccccc   ooooo    mmmmmmmmm   eeeeeee      !!!!\n");
printf("w      w      w e      e   l       c        o      o   m    m    m   e      e      !!! \n");
printf(" w    w w    w   e eeeee   l       c       o        o m    m    m   eeeeeee      !!   \n");
printf("   w w    w w    e         l       c        o      o   m    m    m   e            !    \n");
printf("    w      w     eeeeeee   llllll ccccccc   ooooo    m    m    m   eeeeeee          \n");
for(;;)
{
int sum=0;
printf("\n");
printf("\t****************MENU*******************************\n");
printf("\t*        Common Algorithm String                      *\n");
printf("\t*         1.Copy string                           *\n");
printf("\t*         2.Comparing strings                         *\n");
printf("\t*         3.Request the length of the string                        *\n");
printf("\t*         4.Connect the two strings                         *\n");

printf("\t*         5.The character ch converted to lower case mother                 *\n");
printf("\t*         6.The character ch converted to upper case letters                  *\n");
printf("\t*         7.Check if the letters ch                        *\n");
printf("\t*         8.Check whether the number of ch                        *\n");
printf("\t*         9.Ch check whether the letters or numbers             *\n");
printf("\t*         10.Check whether ch capital letters (A - Z)        *\n");
printf("\t*         11.Check whether ch lowercase letters (a - z)          *\n");
printf("\t*         12.Quit                                   *\n");
printf("\t***************************************************\n");
printf("\nPlease choose the number n:");
scanf("%d",&n);
while (n<=0||n>13)
    {
         printf("Please choose the number again n:");
         scanf("%d",&n);
    }
switch( n)
     {
         case 1:                         /*字符串的复制*/
                  clrscr();
                  getchar();             /*抵消回车*/
                  printf("input string1:");

                  gets(s1);
                  j=0;
                  for (i=0;s1[i]!='\0';i++) s2[i]=s1[i];
                  printf("\nThe new string is:%s\n", s2);
                  break;

         case 2:
                  clrscr();
                  getchar();                                            /*字符串的比较 */
                  printf("\ninput string1:");
                  gets(s1);
                  printf("\ninput string2:");
                    gets(s2);
                    i=0;
                   while ((s1[i]==s2[i])&&(s1[i]!='\0'))i++;
                   if (s1[i]=='\0'&& s2[i]=='\0')      resu =0;
                   else
                  resu=s1[i]-s2[i];
                    if(resu==0)
                   printf("s1=s2");
                    else if(resu>0)
                    printf("s1>s2");

                    else
                    printf("s1<s2");
                  break;
         case 3:
                 clrscr();
                 getchar();                                                /*求字符串的长度   */
                 printf("\ninput string:");
                 gets(s);
                 for(i=0;s[i]!='\0';i++)
                 sum=sum+1;
                 printf("The length of the string is:%d", sum);
                 break;
         case 4:
                clrscr();
                j=0;
                i=0;
                getchar();                                               /*连接两个字符*/
                printf("\nput string1:");
                gets(s1);
                printf("input string2:");
                gets(s2);
                while(s1[i]!='\0')
                 i++;

                while(s2[j]!='\0')
                s1[i++]=s2[j++];
                s1[i]='\0';
                printf("the new string is:%s\n",s1);
                break;
         case 5:
                clrscr();
                printf("input string:");      /*将ch字符转换为小写母*/
                getchar();
                gets(s);
                for(i=0;s[i]!='\0';i++)
                if(s[i]>=65 && s[i]<=90)
                printf("%c",s[i]);
                else if(s[i]>=97 && s[i]<=122)
                {s[i]=s[i]-32;
                printf("%c",s[i]);
                }
                else
                printf("%c",s[i]);
                break;
         case 6:
                 clrscr();
                 getchar();
                 printf("input string:");                      /*将ch字符转换为大写字母 */
                 gets(s);
                 for(i=0;s[i]!='\0';i++)

                 if(s[i]>=97 && s[i]<=122)
                 printf("%c",s[i]);
                 else if(s[i]>=65 && s[i]<=90)
                 {s[i]=s[i]+32;
                 printf("%c",s[i]);
                 }
                 else
                 printf("%c",s[i]);
                 break;
         case 7:
                clrscr();
                 getchar();                                           /*检查ch是否是字母 */
                printf("input   string :");
                gets(s);
                 for(i=0;s[i]!='\0';i++)
                {
                    if( (s[i]>=65 && s[i]<=90) || (s[i]>=97 && s[i]<=122)||(s[i]==' '))
                 continue;
                 else
                 k=1;
                }
                if(k==0)
                printf("The string is   alpha.");
                else

                printf("The string is not alpha.");
                break;
         case 8:
                clrscr();
                getchar();                                            /*检查ch是否是数字 */
                printf("input   string :");
                gets(s);
                for(i=0;s[i]!='\0';i++)
                {if( (s[i]>=48 && s[i]<=57) || (s[i]==' '))
                continue;
                else
                k=1;}
                if(k==0)
                printf("The string is   numeric.");
                else
                printf("The string is not numeric.");
                break;
         case   9:                                                  /* 检查ch是否由字母或数字组成   */
                clrscr();
                k=0;
                getchar();

                printf("input   string :");
                 gets(s);
                 for(i=0;s[i]!='\0';i++)
                {
                if((s[i]>=65 && s[i]<=90) || (s[i]>=97 && s[i]<=122)||(s[i]==' ')|| (s[i]>=48 && s[i]<=57) )
                continue;

                k=1;}
                if(k==0)
                printf("The string is   numeric or alpha .");
                else
                printf("The string is not numeric or alpha.");
                break;
         case 10:                                       /*检查ch是否大写字母（A——Z）*/
                clrscr();
                getchar();
                printf("input   string :");
                gets(s);
                for(i=0;s[i]!='\0';i++)
                {
                if( (s[i]>=65 && s[i]<=90) ||(s[i]==' '))
                continue;

                else
                k=1;
                }
                if(k==0)
                printf("The string is capital letter.");
                else
                printf("The string is not capital letter.");
                break;
         case 11:
                clrscr();
                getchar();
                printf("input   string :");
                gets(s);
                for(i=0;s[i]!='\0';i++)
                {
                if( (s[i]>=97 && s[i]<=122) ||(s[i]==' '))
                continue;
                else
                k=1;
                }
                if(k==0)
                printf("The string is small letter.");
                else
                printf("The string is not small letter.");
                break;

          case 12:
                clrscr();            /*退出界面*/
                printf("\n");
                printf("\tBBBBB       Y      Y       BBBBB     !!!!!     \n");
                  printf("\tB      B      Y    Y        B      B   !!!!      \n");
                 printf("\tBBBBB          Y          BBBB      !!!       \n");
                 printf("\tB      B        Y          B      B   !!        \n");
                 printf("\tBBBBB          Y          BBBBB     !         \n");
      }
}
}

日	一	二	三	四	五	六

高手帮我看看，改错，谢谢

扫二维码下载贴吧客户端