水仙花数是指一个 n 位数 ( n≥3 ),它的每个位上的数字的 n 次幂之和等于它本身。(例如:1^3 + 5^3 + 3^3 = 153,1634 = 1^4 + 6^4 + 3^4 + 4^4)。
给出一个整数M,求 >= M的最小的水仙花数。
Input
一个整数M(10 <= M <= 10^60)
Output
输出>= M的最小的水仙花数,如果没有符合条件的水仙花数,则输出:No Solution
Input示例
300
Output示例
370

一道賊变态的题,如果按常规出牌,绝对做不出来,必然会超时,或者说,我肯定是做不成的。
但是如果投机取巧,那么这就是一道很简单的题,虽然它数据范围高达60位,但是水仙花数却是有限的,只有89个,所以,我们完全可以打表做题。那么剩下的问题就出现了,这些水仙花数是啥?

想知道这些数都是啥,可以选择两种手段,第一暴力解题,获得数据,但是我想这也忒复杂了,虽然是暴力解题,但是依然存在很多问题,就算你写出来代码,想获得所有的水仙花数依然需要很长很长时间等待哦,毕竟运算量惊人。
于是我只好选择第二种办法了,找度娘喽……

这是水仙花数……

0
1
2
3
4
5
6
7
8
9
153
370
371
407
1634
8208
9474
54748
92727
93084
548834
1741725
4210818
9800817
9926315
24678050
24678051
88593477
146511208
472335975
534494836
912985153
4679307774
32164049650
32164049651
40028394225
42678290603
44708635679
49388550606
82693916578
94204591914
28116440335967
4338281769391370
4338281769391371
21897142587612075
35641594208964132
35875699062250035
1517841543307505039
3289582984443187032
4498128791164624869
4929273885928088826
63105425988599693916
128468643043731391252
449177399146038697307
21887696841122916288858
27879694893054074471405
27907865009977052567814
28361281321319229463398
35452590104031691935943
174088005938065293023722
188451485447897896036875
239313664430041569350093
1550475334214501539088894
1553242162893771850669378
3706907995955475988644380
3706907995955475988644381
4422095118095899619457938
121204998563613372405438066
121270696006801314328439376
128851796696487777842012787
174650464499531377631639254
177265453171792792366489765
14607640612971980372614873089
19008174136254279995012734740
19008174136254279995012734741
23866716435523975980390369295
1145037275765491025924292050346
1927890457142960697580636236639
2309092682616190307509695338915
17333509997782249308725103962772
186709961001538790100634132976990
186709961001538790100634132976991
1122763285329372541592822900204593
12639369517103790328947807201478392
12679937780272278566303885594196922
1219167219625434121569735803609966019
12815792078366059955099770545296129367
115132219018763992565095597973971522400
115132219018763992565095597973971522401

看着好爽啊,这么长……

接下来要考虑的问题就是比大小,这也好解决,位数不同的比位数,相同的再逐位比大小。大概就是这个样子吧。剩下的就没有什么难点了。

代码(C):

#include <stdio.h>
#include <string.h>

int compare(char *a, char *b, int len)
{
    for (int i = 0; i < len; i++)
    {
        if (b[i] > a[i])
        {
            return 1;
        }
        else if (b[i] < a[i])
        {
            return 0;
        }
    }
    return 1;
}

int main(int argc, const char * argv[])
{
    char NarNum[89][60] = {
  "0","1","2","3","4","5","6","7","8","9","153","370","371","407","1634","8208","9474","54748","92727","93084","548834","1741725","4210818","9800817","9926315","24678050","24678051","88593477","146511208","472335975","534494836","912985153","4679307774","32164049650","32164049651","40028394225","42678290603","44708635679","49388550606","82693916578","94204591914","28116440335967","4338281769391370","4338281769391371","21897142587612075","35641594208964132","35875699062250035","1517841543307505039","3289582984443187032","4498128791164624869","4929273885928088826","63105425988599693916","128468643043731391252","449177399146038697307","21887696841122916288858","27879694893054074471405","27907865009977052567814","28361281321319229463398","35452590104031691935943","174088005938065293023722","188451485447897896036875","239313664430041569350093","1550475334214501539088894","1553242162893771850669378","3706907995955475988644380","3706907995955475988644381","4422095118095899619457938","121204998563613372405438066","121270696006801314328439376","128851796696487777842012787","174650464499531377631639254","177265453171792792366489765","14607640612971980372614873089","19008174136254279995012734740","19008174136254279995012734741","23866716435523975980390369295","1145037275765491025924292050346","1927890457142960697580636236639","2309092682616190307509695338915","17333509997782249308725103962772","186709961001538790100634132976990","186709961001538790100634132976991","1122763285329372541592822900204593","12639369517103790328947807201478392","12679937780272278566303885594196922","1219167219625434121569735803609966019","12815792078366059955099770545296129367","115132219018763992565095597973971522400","115132219018763992565095597973971522401"};
    int NarNumLen;
    char num[60];
    scanf("%s", num);
    int NumLen = (int)strlen(num);
    for (int i = 0; i < 89; i++)
    {
        NarNumLen = (int)strlen(NarNum[i]);
        if ((NumLen == NarNumLen && compare(num, NarNum[i], NumLen)) || NumLen < NarNumLen)
        {
            printf("%s\n", NarNum[i]);
            return 0;
        }
    }

    puts("No Solution");
    return 0;
}