[C++知识库]PAT-A1073(C/C++代码解析)

1073 Scientific Notation (20 分)

注：字符串处理

#include <stdio.h>
#include <string.h>
int main ()
{
	char z[100001];
	scanf ("%s",z);
	if (z[0]=='-')
	printf ("-");
	int i,j,l=strlen(z),id,e;
	for (i=0;i<l;i++)
	{
		if (z[i]=='E')
		{
			id=i;
			break;
		}
	}
    int w,sum=0;
    for (w=id+2;w<l;w++)
	sum=sum*10+(z[w]-'0');
    if(sum==0)
    {
        for (int qq=1;qq<id;qq++)
            printf ("%c",z[qq]);
    }
    else
	{
		if (z[id+1]=='-')
		{
	        e=sum;
			printf ("0.");
			for (i=0;i<e-1;i++)
			printf ("0");
			printf ("%d",(z[1]-'0'));
			for (i=3;i<id;i++)
			printf ("%d",(z[i]-'0')); 
		}
		else if (z[id+1]=='+')
		{
 	       e=sum;
 	       printf ("%d",(z[1]-'0'));
		   for (i=3;i<3+e&&i<id;i++)
		   printf ("%d",(z[i]-'0'));
		   if (i<id)
		   {
		    	printf (".");
		    	for (j=i;j<id;j++)
		    	printf ("%d",(z[j]-'0'));
	    	}
	    	else
	    	{
	    		for (j=0;j<e-(id-3+1)+1;j++)
	    		printf ("0");
	    	}
    	}
    }
	return 0;
}