CodeForces 552C-Vanya and Scales【思维】

C. Vanya and Scales
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Vanya has a scales for weighing loads and weights of masses w0, w1, w2, ..., w100 grams where w is some integer not less than 2(exactly one weight of each nominal value). Vanya wonders whether he can weight an item with mass m using the given weights, if the weights can be put on both pans of the scales. Formally speaking, your task is to determine whether it is possible to place an item of mass m and some weights on the left pan of the scales, and some weights on the right pan of the scales so that the pans of the scales were in balance.

Input

The first line contains two integers w, m (2 ≤ w ≤ 1091 ≤ m ≤ 109) — the number defining the masses of the weights and the mass of the item.

Output

Print word 'YES' if the item can be weighted and 'NO' if it cannot.

Examples
input
3 7
output
YES
input
100 99
output
YES
input
100 50
output
NO
Note

Note to the first sample test. One pan can have an item of mass 7 and a weight of mass 3, and the second pan can have two weights of masses 9 and 1, correspondingly. Then 7 + 3 = 9 + 1.

Note to the second sample test. One pan of the scales can have an item of mass 99 and the weight of mass 1, and the second pan can have the weight of mass 100.

Note to the third sample test. It is impossible to measure the weight of the item in the manner described in the input.

解题思路:
公式是这样,a w 0  +a w 1  +a w 2    ...+a w 100 =m,a的取值只能是-1,0,1。我们只需要模拟这个过程。













<pre name="code" class="cpp">#include<cstdio>
int main()
{
	long long w,m;
	while(scanf("%lld%lld",&w,&m)!=EOF)
	{
		if(w<=3)
		{
			printf("YES\n");
			continue;
		}
		//int cnt=0;
		int av3344=0;
		for(;m!=0;)
		//while(m)
		{
			if(((m+1)%w)==0)
			{
				m++; 
			}
			else if(((m-1)%w)==0)
			{
				m--;
			}
			else if(m%w!=0)
			{
				av3344=1;
				printf("NO\n");
				break;
			}
			m=m/w;
			//++cnt;
		}
	//	printf("%d\n",cnt);
		if(av3344==0)
		printf("YES\n");
	}
	return 0;
}

 
       

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