Digital Roots Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 57857 Accepted Submission(s): 18070 Problem Description The digital root of a positive integer is found by summing the digits of the i…
#include<stdio.h> #include<stdlib.h> //快速幂算法,数论二分 long long powermod(int a,int b, int c) //不用longlong就报错,题目中那个取值范围不就在2的31次方内 { long long t; if(b==0) return 1%c; if(b==1) return a%c; t=powermod(a,b/2,c);//递归调用,采用二分递归算法,,注意这里n/2会带来奇偶性问题 t=t*t%c;…
Description There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. From a tile, he can move to one of four adjacent tiles. But he can't move on red tiles, he can move only…
