8-21.cpp

能判断二次函数是否有根

/*3208006411*/
#include<stdio.h>
#include<string.h>
void main()
{int strl(char array[],int );
int i,length,n;
char string[100];
printf("please input the character string:\n");
for(i=0,n=0; ;i++)
{scanf("%c",&string[i]);
if(string[i]==' ')
  break;
else n++;}
length=strl(string,n);
printf("the length of character string is %d",length);
}
int strl(char array[],int n)
{int i,j=0;
{for(i=0;i<n+1;i++)
  if(array[i]!='\0')
    j=j+1;}
 j=j-1;
return(j);
}