Question

合法C语言标识符

给定n个不包含空白符的字符串，请判断他们是否是C语言合法的标识符号
#include<stdio.h>
int main()
{
int n;
char sr[100][100];
int i,j,sum[100];
scanf("%d",&n);
for(i=0;i<n;i++) gets(sr[i]);
for(i=0;i<n;i++){
sum[i]=0;
for(j=0;sr[i][j]!='\0';j++){
if((sr[i][j]>='A'&&sr[i][j]<='Z')||(sr[i][j]>='a'&&sr[i][j]<='z')||(sr[i][j]>='0'&&sr[i][j]<='9')||(sr[i][0]=='_')&&(sr[i][0]<='0'&&sr[i][0]>='9')) sum[i]=1;
else{
sum[i]=0;
break;
}
}
if(sum[i]==0) printf("no\n");
else printf("yes\n");
}

return 0;
}

为什么实现不了功能呢？

Answer 1

#include<stdio.h>
int main()
{
int n;
char sr[100][100];
int i,j,sum[100];
scanf("%d",&n);
char ddd;
scanf("%c",&ddd);
for(i=0;i<n;i++) gets(sr[i]);
for(i=0;i<n;i++)
{
sum[i]=0;
for(j=0;sr[i][j]!='\0';j++)
{
if(j==0)
{
if( (sr[i][j]>='A'&&sr[i][j]<='Z')||
(sr[i][j]>='a'&&sr[i][j]<='z')||
(sr[i][j]=='_'))sum[i]=1; else
{
sum[i]=0;
break;
}
}

else if(j>0)
{
if ((sr[i][j]>='A'&&sr[i][j]<='Z')||
(sr[i][j]>='a'&&sr[i][j]<='z')||
(sr[i][j]=='_') ||
(sr[i][j]>='0'&&sr[i][j]<='9'))sum[i]=1;
else
{
sum[i]=0;
break;
}
}

else
{
sum[i]=0;
break;
}
}
if(sum[i]==0) printf("no\n");
else printf("yes\n");
}

return 0;
}

Answer 2