因为:123 * 45 = 14 +15 +24 +25 +34+35 = 3*(4+5)+2*(4+5)+1*(4+5) 所以根据规律,代码如下:
int main(){
int a,b,m,n,sum1,sum2;
while(~scanf("%d %d",&a,&b))
{
m=0,n=0,sum1=0,sum2=0;
while(b>0){
sum1+=b%10;
b/=10;
}
while(a>0)
{
m=a%10;
a/=10;
sum2+=m*sum1;
}printf("%d\n",sum2);
}
}