PAT(Basic Level)_1010_一元多项式求导

//借鉴了网上的思路
#include<stdio.h>

int main(){
int exp,coe,flag=0;

while(scanf("%d%d",&coe,&exp)!=EOF){
coe=coe*exp;
exp--;
if(coe){
if(flag) putchar(' ');
else flag=1;
printf("%d %d",coe,exp);
}
}
if(!flag) printf("0 0");

return 0;
}