uva 3n+1 问题

[wangmm2008]

参考一博客中的java写的解决方法，我用C写了一个，但是Java的能通过，C的超时，不知道哪里有问题

#include <stdio.h>
#define MAX 1000000
static int cache[MAX] = {0};

long long next(long long n){
	if(n & 1)
		return n + (n << 1)+1;
	else
		return (n >> 1);
}

int cl(long long n){
	int l;

	if(n == 1)
		return 1;
	if(n < MAX && cache[(int)n] != 0)
		return cache[(int)n];
	l = cl(next(n))+1;
	if(n < MAX)
		cache[(int)n] = l;
	return l;	
}

int main(){
	int start,end,i,r,max,tmp,s,e;

	printf("Input start&end:\n");
	while(scanf("%d%d",&start,&end)){
		s = start;
		e = end;
		if(start > end){
			tmp = start;
			start = end;
			end = tmp;
		}
		max = 0;	/*critical*/
		for(i = start; i <= end; ++i){
			r = cl(i);
			if(max < r)
				max = r;
		}
		printf("%d %d %d\n",s,e,max);
	}
}

###################################################

import java.util.*;
import java.math.*;
import java.io.*;
public class Main {
	// cache for already computed cycle lengths
	public static int[] cache = new int[1000000];
	// a function that returns the
	// next number in the sequence
	public static long next(long n) {
		if (n % 2 == 0)
			return n / 2;       // if n is even
		else
			return 3 * n + 1;   // if n is odd
	}
	public static int cycleLength(long n) {
		// our base case
		// 1 has a cycle length of 1
		if (n == 1)
			return 1;
		// check if we've already cached the
		// cycle length of the current number
		if (n < 1000000 && cache[(int)n] != 0)
			return cache[(int)n];
		// the cycle length of the current number is 1 greater
		// than the cycle length of the next number
		int length = 1 + cycleLength(next(n));
		// we cache the result if the
		// current number is not too big
		if (n < 1000000)
			cache[(int)n] = length;
		return length;
	}
	public static void main(String[] args) throws Exception {
		Scanner in = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out, true);

		// while there is some input to read
		while (in.hasNextInt()) {
			int i = in.nextInt(),
			    j = in.nextInt(),
			    from = Math.min(i, j),
			    to = Math.max(i, j),
			    max = 0;
			// loop through all the numbers
			// and find the biggest cycle
			for (int n = from; n <= to; n++) {
				max = Math.max(max, cycleLength(n));
			}
			out.printf("%d %d %d\n", i, j, max);
		}
	}
}

[没事人]

会不会是数组太大了

[wangmm2008]

引用 1 楼 u013697891 的回复:

会不会是数组太大了

应该不是这个原因，java代码中也有那个大数组，但是java的过了

[FancyMouse]

while(scanf("%d%d",&start,&end) == 2) 另外不要输出 printf("Input start&end:\n"); 这种多余的东西