新手编了一个程序，找不到问题所在

Question

#include
int main (void)
{
int i , j ;
long int sum = 0,n = 0;
for (i=1;i <= 9;i++)
{
for(j=i;j <=9;j++)
{
n = n*10 + i;
sum += n;
if(j==9)
printf( "%ld= ",n);
else
printf( "%ld+ ",n);
}
printf( "%ld\n ",sum);
}
return 0;

}

以上是我的程序，编译环境是vc++6.0...........
题目是：1+11+111+…[phone]=
2+22+222+…[phone]=
.....................................................
9+99+999+…[phone]=
用C语言如何编程求和？

Answer 1

#include
int main (void)
{
long i , j ;
long int sum = 0,n = 0;
for (i=1;i <= 9;i++)
{
for(j=1;j <=9;j++)
{
n = n*10 + i;
sum += n;
if(j==9)
printf( "%ld= ",n);
else
printf( "%ld+ ",n);
}
printf( "%ld\n ",sum);
sum=0;
n=0;
}
return 0;
}