ct.cpp

一般来说用int型变量超过2^31的数就会溢出。此程序是利用数组对长度很长的整形字符串进行加减操作

#include <iostream.h>

const int NUMBER=30;
const int GAP=2; //it makes error result when GAP is bigger than 2

int getNext(int *pNum, int begin)
{
	begin;
	int count=0;
	for(int i=begin;;i++)
	{
		if (0==*(pNum+i)) break;
		else count++;
		if (2==*(pNum+i)) 
		{
			i=0;
			if(0==*(pNum+i)) break;
		}
		if (count>=NUMBER) return 0;
	}
	return i+1;
}

void main()
{
	int array[NUMBER+1]={0};
	array[NUMBER]=2;	//terminate number
	int begin=1,next=1; int last=0;
	array[begin-1]=1;
	while(0!=next)
	{
		for(int i=0; i<GAP; i++)
			next=getNext(array, next);
		if(0!=next) { array[next-1]=1; last=next; }
		else break;
	}
	cout<<"The last peason left is "<<last<<endl;
}