#include<stdio.h>
 int main()
 {
 int i,a[10];
 for(i=0;i<=9;i++)
 a[i]=i;
 for(i=9;i>=0;i--)
 printf("%d ",a[i]);
 printf("\n");
 return 0;
 }
 #include<stdio.h>
 int main()
 {
 int i,a[10];
 for(i=0;i<=9;i++)
 a[i]=i;
 for(i=9;i>=0;i--)
 printf("%d ",a[i]);
 printf("\n");
 return 0;
 }

The operation results are as follows

Example 6.2 solving Fibonacci sequence with array

#include<stdio.h>
int main()
{
int i;
int f[20]={1,1};
for(i=2;i<20;i++)
f[i]=f[i-2]+f[i-1];
for(i=0;i<20;i++)
{
if(i%5==0)  printf("\n");
printf("%12d",f[i]);
}
printf("\n");
return 0;
}

The operation results are as follows:

Example 6.3 there are 10 areas, which need to be arranged in order of small to large

#include<stdio.h>
int main()
{
int a[10];
int i,j,t;
printf("input 10 numbers:\n");
for(i=0;i<10;i++)
scanf("%d",&a[i]);
printf("\n");
for(j=0;j<9;j++)
for(i=0;i<9-j;i++)
if(a[i]>a[i+1])
{t=a[i];a[i]=a[i+1];a[i+1]=t;}
printf("the sorted numbers:\n");
for(i=0;i<10;i++)
printf("%d ",a[i]);
printf("\n");
return 0;
}

The operation results are as follows

Example 6.4 interchange the elements of a two-dimensional array row and column and store them in another two-dimensional array

#include<stdio.h>
int main()
{
  int a[2][3]={{1,2,3},{4,5,6}};
  int b[3][2],i,j;
  printf("array a:\n");
  for(i=0;i<=1;i++)
{
 for(j=0;j<=2;j++)
{
printf("%5d",a[i][j]);
b[j][i]=a[i][j];
}
printf("\n");
}
printf("array b:\n");
for(i=0;i<=2;i++)
{
for(j=0;j<=1;j++)
printf("%5d",b[i][j]);
printf("\n");
}
return 0;
 }

The operation results are as follows:

Example 6.5 has a 3 * 4 matrix, which requires the program to find out the element with the largest value, as well as the row number and column number

#include<stdio.h>
int main()
{ int i,j,row=0,colum=0,max;
int a[3][4]={{1,2,3,4},{9,8,7,6},{-10,10,-5,2}}; 
max=a[0][0];
for(i=0;i<=2;i++)
for(j=0;j<=3;j++)
if(a[i][j]>max)
{max=a[i][j];
row=i;
colum=j;
}
printf("max=%d\nrow=%d\ncolum=%d\n",max,row,colum);
return 0;
}

The operation results are as follows:

Example 6.6 output a known string

#include<stdio.h>
int main()
{
char c[15]={'I',' ','a','m',' ','a','s','t','d','e','n','t','.'};
int i;
for(i=0;i<15;i++) 
printf("%c",c[i]);
printf("\n");
return 0;
}

The operation results are as follows:

Example 6.7 output a diamond

#include<stdio.h>
int main()
{char diamond[ ][5]={{' ',' ','*'},{' ','*',' ','*'},{'*',' ',' ',' ','*'},{' ','*',' ','*'},{' ',' ','*'}};
int i,j;
for(i=0;i<5;i++)
{ for(j=0;j<5;j++)
printf("%c",diamond[i][j]);
printf("\n");
}
return 0;
}

The operation results are as follows:

Example 6.9 there are three strings to find the "largest" one

#include<stdio.h>
#include<string.h>
int main()
{
char str[3][20];
char string[20];
int i;for(i=0;i<3;i++)
gets(str[i]);
if(strcmp(str[0],str[1])>0)
strcpy(string,str[0]);
else strcpy(string,str[1]);
if(strcmp(str[2],string)>0)
strcpy(string,str[2]);
printf("\nthe largest string is:\n%s\n",string); 
return 0;
}

The operation results are as follows:
Data)