HDU 1097
2014-04-30 18:34
211 查看
取a的最后一位0-9,发现乘方个位数有周期关系(可以证明不大于4),找到周期和周期里对应的数,对于b直接查找即可
#include<stdio.h> int T[5]; int main() { int a,b,i,j,temp,t,d; while(~scanf("%d%d",&a,&b)) { t = 0; temp = 1; a %= 10; if(a==1) { printf("1\n"); continue ; } d = a; while(temp != a) { T[t++] = d; temp = (d*a)%10; d = temp; } t = (b%t==0?t-1:b%t-1); printf("%d\n",T[t]); } return 0; }