PHP实现

时间复杂度O(n)

$n = "9875";
$n_size = strlen($n);
for($i = $n_size-1; $i > 0; $i-- ) {
     if($n[$i] > $n[$i-1]){
     $temp = $n[$i];
     $n[$i] = $n[$i-1];
     $n[$i-1] = $temp;
     break;
     }
    
}

if($i == 0){
    echo "Next Greater value no possible";
}else{
    echo $n;
}

int t,k,num3,num5;
scanf("%d",&t);
int num[t];
for(int i=0;i<t;i++){
    scanf("%d",&num[i]);   
}
for(int i=0;i<t;i++){
    k=(((num[i]-1)/3)+1); 
    if(k<0)
        printf("-1");
    else if(num[i]<3 || num[i]==4 || num[i]==7)
        printf("-1");
    else{
        num3=3*(2*num[i] - 5*k);
        num5=5*(3*k -num[i]);
        for(int j=0;j<num3;j++)
            printf("5");
        for(int j=0;j<num5;j++)
            printf("3");
    }
    printf("\n");
}

我们需要找到最右边的0位，后面是1，然后将最右边的0位翻转为1。

例如，我们的输入是487，也就是二进制的111100111。

我们把后面有1的0往右翻转最多

所以我们得到 111101111

但是现在我们多了一个1，少了一个0，所以我们减少了右边1的个数 位增加1，并将0位的no增加1，得到

111101011 -二进制491

int getNextNumber(int input)
{
    int flipPosition=0;
    int trailingZeros=0;
    int trailingOnes=0;
    int copy = input;

    //count trailing zeros
    while(copy != 0 && (copy&1) == 0 )
    {
        ++trailingZeros;

        //test next bit
        copy = copy >> 1;
    }

    //count trailing ones
    while(copy != 0 && (copy&1) == 1 )
    {
        ++trailingOnes;

        //test next bit
        copy = copy >> 1;
    }

    //if we have no 1's (i.e input is 0) we cannot form another pattern with 
    //the same number of 1's which will increment the input, or if we have leading consecutive
    //ones followed by consecutive 0's up to the maximum bit size of a int
    //we cannot increase the input whilst preserving the original no of 0's and
    //1's in the bit pattern
    if(trailingZeros + trailingOnes  == 0 || trailingZeros + trailingOnes == 31)
        return -1;

    //flip first 0 followed by a 1 found from the right of the bit pattern
    flipPosition = trailingZeros + trailingOnes+1;
    input |= 1<<(trailingZeros+trailingOnes);

    //clear fields to the right of the flip position
    int mask = ~0 << (trailingZeros+trailingOnes);
    input &= mask;

    //insert a bit pattern to the right of the flip position that will contain
    //one less 1 to compensate for the bit we switched from 0 to 1
    int insert = flipPosition-1;
    input |= insert;

    return input;
}

至少，这里有几个基于字符串的暴力解决方案的例子，你应该能够马上想到:

38276中的数字排序为23678

38627排序的数字列表是23678

蛮力增量，排序和比较

沿着蛮力解决方案将转换为字符串 然后用这些数字强行找出所有可能的数字。

从它们中创建int，把它们放在一个列表中并排序， 获取目标条目之后的下一个条目。

如果你花了30分钟在这个问题上，却没有想出一个蛮力的方法，我也不会雇用你。

在商业世界中，一个不优雅、缓慢和笨拙但能完成工作的解决方案总是比没有解决方案更有价值，事实上，这几乎描述了所有不优雅、缓慢和笨拙的商业软件。

只是使用python的另一个解决方案:

def PermutationStep(num):
    if sorted(list(str(num)), reverse=True) == list(str(num)):
        return -1
    ls = list(str(num))
    n = 0
    inx = 0
    for ind, i in enumerate(ls[::-1]):
        if i < n:
            n = i
            inx = -(ind + 1)
            break
        n = i
    ls[inx], ls[inx + 1] = ls[inx + 1], ls[inx]

    nl = ls[inx::-1][::-1]
    ln = sorted(ls[inx+1:])
    return ''.join(nl) + ''.join(ln)

print PermutationStep(23514)

输出:

23541

回答在java与一个更多的条件添加

Next number should also be an Even number public static int nextDigit(int number) { String num = String.valueOf(number); int stop = 0; char[] orig_chars = null; char[] part1 = null; char[] part2 = null; orig_chars = num.toCharArray(); System.out.println("vivek c r"); for (int i = orig_chars.length - 1; i > 0; i--) { String previous = orig_chars[i - 1] + ""; String next = orig_chars[i] + ""; if (Integer.parseInt(previous) < Integer.parseInt(next)) { if (Integer.parseInt(previous) % 2 == 0) { String partString1 = ""; String partString2 = ""; for (int j = 0; j <= i - 1; j++) { partString1 = partString1.concat(orig_chars[j] + ""); } part1 = partString1.toCharArray(); for (int k = i; k < orig_chars.length; k++) { partString2 = partString2.concat(orig_chars[k] + ""); } part2 = partString2.toCharArray(); Arrays.sort(part2); for (int l = 0; l < part2.length; l++) { char temp = '0'; if (part2[l] > part1[i - 1]) { temp = part1[i - 1]; part1[i - 1] = part2[l]; part2[l] = temp; break; } } for (int m = 0; m < part2.length; m++) { char replace = '0'; if (part2[m] % 2 == 0) { replace = part2[m]; for (int n = m; n < part2.length - 1; n++) { part2[n] = part2[n + 1]; } part2[part2.length - 1] = replace; break; } } System.out.print(part1); System.out.println(part2); System.exit(0); } } } System.out.println("NONE"); return 0; }