作业3

Homework Three
Part One : Please select correct answer from A,B,C and D ,there is only one correct item.
D1. After declaration : int a[20]; which explanation is NOT true 。

A) The type of array a is int
B) There are 20 elements in the array .
C) The array holds sizeof(a) bytes of memory
D) The subscript should start from 1 to 20 .
B2. After declaration :int a[ ][3]={1,2,3,4,5,6,7} ；the number of raws is 。

A) 2 B) 3 C) 4 D) not sure
C3. From the following explanation of character array , which is NOT ture 。

A) Character array can be used to store string
B) Character array can be input or output in the form of string
C) The elements of character array can’t be accessd individually
D) The subscript of character array is from 0 .
C4 which is the correct expression if assign‘g’ to char variable c。

A) c=\147 B) c=”\147”C) c=’\147’D) c=’0147’
B5 The length of the str ing : ”\”EOF\n=-\61\””is ____ 。

A) 8 B) 9 C) 14 D) wrong string
B6. After declaration ：char str1[10] ，str2[10]={"books"} ；which statement assign string "books" to array str1 。

A) str1 = {"Books"}; B) strcpy (str1,str2);
C) str1 = str2; D) strcpy (str2,str1);
D7 After the declaration int a[3][2]={3,2,1} ；the value of the expression
a[0][0]/a[0][1]/a[0][2] is ____ 。

A) 0.166667 B) 1 C) 0 D) error
8 The following program is used to sort data in decreasing order ( N is the number of value )
#define N 20
main
{ int i, j, m, end=0, a[N];
for ( i=0; i<N; i++ )
scanf("%d", &a[i]);
for ( j=0; j<N-1 && ①B ; j++ )
{ ②B;
for ( i=0; i<N-j; i++ )
if ( ③A )
{ m=a[i];
a[i]=a[i+1];
a[i+1]=m;
end=0;
}
}
for ( i=0; i<N; i++ )
printf ("%5d", a[i] );
}
①A) end B) !end C) end==1 D) end!=0
②A) end=0 B) end=1 C) m=0 D) m=1
③A) a[i]<a[i+1] B) a[i]>a[i+1] C) a[i]<a[j] D) a[i]>a[j]
9 ．We have a increasing sorted string a ，the following program is to insert another string s to a, the result should be in the increasing order too .
char a[20] = "cehiknqtw";
char s[ ] = "fbla";
main
{ int i, k, j;
for ( k=0; s[k]!= '\0'; k++ )
{ j=0;
while ( s[k]>=a[j] && a[j]!= ①A )
j++;
for ( ②B )
③B ;
a[j]=s[k];
}
puts(a);
}
①A) '\0' B) '\n' C) '\t' D) '\b'
②A) i=strlen(a)+k; i>=j; i-- B) i=strlen(a); i>=j; i--
C) i=j; i<=strlen(a)+k; i++ D) i=j; i<=strlen(a); i++
③A) a[i]=a[i+1] B) a[i+1]=a[i]
C) a[i]=a[i-1] D) a[i-1]=a[i]
Part Two :Filling the blands in order to get correct result
10 The program is used to get the maximum value of the array s which has n members.
#define N 20
main()
{ int i,a[N] ；
for(i=0 ；i<N ；i++)
scanf(“%d”,&a[i]) ；
printf(“%d\n”,①a[fmax(a,N)] ) ；
}
fmax(int s[],int n)
{ int k,p ；
for(p=0,k=p ；p<n ；p++)
if(s[p]>s[k]) ②k=p；
return(k) ；
}
11. The result of following program is : i= ①4，s+i= ②efgh。

char s[ ]="abcdefgh";
main
{ int i=0;
while(s[i++]!='d');
printf("%d %s\n", i, s+i);
}
12. The result of following program is ①3和②5。

fun ( int a )
{ static int m=2;
m += a;
return (m);
}
main ()
{ printf ("%d\n", fun(1)); /* ①*/
printf ("%d\n", fun(2)); / * ②*/
}
13. The program is to get the all palindrome ( 回文) primes ( 质数) between 100 to 999 . such as 12321 is a palindrome ，both 151 and 919 are 3 digits palindrome primes .
#include <stdio.h>
main
{ int i, j, s;
printf ("\nFollowing are palindrome primes not greater than 1000:\n");
for ( i=1; i<=9; i+=2 )
main
{ float x=10, y=20;。