joj1006 十进制转换成base进制

#include <stdio.h>
#include <string.h>
int a[20];
int b[20];
//将十进制数转化成 base进制
void baseConvert(int num,int * array,int base)
{
	int i = 0;
	while(num)
	{
		array[i] = num % base;		
		num = num / base;
		i++; 
	}
}
void basePrint(int * arr)
{
	int i = 0;
	while(arr[i] != -1)
		i++;
	for(i=i-1;i>-1;i--)
		printf("%d",arr[i]);
}
void calculate(int base,int x,int y)
{
	baseConvert(x,a,base);
	baseConvert(y,b,base);
	int k = 0; //这个是进位
	int i = 0;
	int res[20];
	//int res[20] = {-1}; 这种初始化不管用
	memset(res,-1,sizeof(res));
	while( a[i] != -1 && b[i] != -1)
	{
		res[i] = a[i] + b[i] + k;
		k = 0;//用过的进位马上清零
		if(res[i] >= base)
		{	
			k = res[i] / base;
			res[i] = res[i] % base;
		}
		i++;
	}
	if(a[i] == -1)
	{
		while(b[i] != -1)
		{
			res[i] = b[i] + k;
			k = 0;
			if(res[i] >= base)
			{
				res[i + 1] = res[i] / base;
				res[i] = res[i] % base;
			}
			i++;
		}		
	}
	if(b[i] == -1)
	{
		while(a[i] != -1)
		{
			res[i] = a[i] + k;
			k = 0; //此处千万记住，用过的进位 一定要清零！！！！！！
			if(res[i] >= base)
			{
				k = res[i] / base;
				res[i] = res[i] % base;			
			}
			i++;
		}
		if( k!= 0)
			res[i] = k;
	}
	basePrint(a);
	printf(" + ");
	basePrint(b);
	printf(" = ");
	basePrint(res);
	printf("\n");
}
int main()
{
	int base,x,y;
	memset(a,-1,sizeof(a));
	memset(b,-1,sizeof(b));
	//while(scanf("%d %d %d",&base,&x,&y),base,x,y)  如果加上 \n 则要输入四个0 才会停止？？？
	while(scanf("%d %d %d",&base,&x,&y),base,x,y)
	{
		calculate(base,x,y);
		memset(a,-1,sizeof(a));
		memset(b,-1,sizeof(b));
	}
	return 0;
}

 如果将那个baseConvert函数修改，则下面的计算将更简单

int baseConvert(int num,int * array,int base)
{
	int i = 0;
	while(num)
	{
		array[i] = num % base;		
		num = num / base;
		i++; 
	}
                return i--;
}