HDOJ1431 素数回文[素数筛选+ltoa函数（将长整形转换成字符数组）+打表]

素数回文

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 7003 Accepted Submission(s): 1612

Problem Description

xiaoou33对既是素数又是回文的数特别感兴趣。比如说151既是素数又是个回文。现在xiaoou333想要你帮助他找出某个范围内的素数回文数，请你写个程序找出 a 跟b 之间满足条件的数。(5 <= a < b <= 100,000,000);

Input

这里有许多组数据，每组包括两组数据a跟b。

Output

对每一组数据,按从小到大输出a，b之间所有满足条件的素数回文数（包括a跟b）每组数据之后空一行。

Sample Input

5 500

Sample Output

5 7 11 101 131 151 181 191 313 353 373 383

Author

xiaoou333

Source

zjut

Recommend

linle

  1 #include<stdio.h>
  2 #include<string.h>
  3 #include<stdlib.h>     //ltoa函数将长整形转换成字符数组
  4 
  5 
  6 
  7 
  8 __int64 num[800]={
  9     5,7,
 10 11,101,131,151,181,191,313,353,
 11 373,383,727,757,787,797,919,929,
 12 10301,10501,10601,11311,11411,12421,12721,12821,
 13 13331,13831,13931,14341,14741,15451,15551,16061,
 14 16361,16561,16661,17471,17971,18181,18481,19391,
 15 19891,19991,30103,30203,30403,30703,30803,31013,
 16 31513,32323,32423,33533,34543,34843,35053,35153,
 17 35353,35753,36263,36563,37273,37573,38083,38183,
 18 38783,39293,70207,70507,70607,71317,71917,72227,
 19 72727,73037,73237,73637,74047,74747,75557,76367,
 20 76667,77377,77477,77977,78487,78787,78887,79397,
 21 79697,79997,90709,91019,93139,93239,93739,94049,
 22 94349,94649,94849,94949,95959,96269,96469,96769,
 23 97379,97579,97879,98389,98689,1003001,1008001,1022201,
 24 1028201,1035301,1043401,1055501,1062601,1065601,1074701,1082801,
 25 1085801,1092901,1093901,1114111,1117111,1120211,1123211,1126211,
 26 1129211,1134311,1145411,1150511,1153511,1160611,1163611,1175711,
 27 1177711,1178711,1180811,1183811,1186811,1190911,1193911,1196911,
 28 1201021,1208021,1212121,1215121,1218121,1221221,1235321,1242421,
 29 1243421,1245421,1250521,1253521,1257521,1262621,1268621,1273721,
 30 1276721,1278721,1280821,1281821,1286821,1287821,1300031,1303031,
 31 1311131,1317131,1327231,1328231,1333331,1335331,1338331,1343431,
 32 1360631,1362631,1363631,1371731,1374731,1390931,1407041,1409041,
 33 1411141,1412141,1422241,1437341,1444441,1447441,1452541,1456541,
 34 1461641,1463641,1464641,1469641,1486841,1489841,1490941,1496941,
 35 1508051,1513151,1520251,1532351,1535351,1542451,1548451,1550551,
 36 1551551,1556551,1557551,1565651,1572751,1579751,1580851,1583851,
 37 1589851,1594951,1597951,1598951,1600061,1609061,1611161,1616161,
 38 1628261,1630361,1633361,1640461,1643461,1646461,1654561,1657561,
 39 1658561,1660661,1670761,1684861,1685861,1688861,1695961,1703071,
 40 1707071,1712171,1714171,1730371,1734371,1737371,1748471,1755571,
 41 1761671,1764671,1777771,1793971,1802081,1805081,1820281,1823281,
 42 1824281,1826281,1829281,1831381,1832381,1842481,1851581,1853581,
 43 1856581,1865681,1876781,1878781,1879781,1880881,1881881,1883881,
 44 1884881,1895981,1903091,1908091,1909091,1917191,1924291,1930391,
 45 1936391,1941491,1951591,1952591,1957591,1958591,1963691,1968691,
 46 1969691,1970791,1976791,1981891,1982891,1984891,1987891,1988891,
 47 1993991,1995991,1998991,3001003,3002003,3007003,3016103,3026203,
 48 3064603,3065603,3072703,3073703,3075703,3083803,3089803,3091903,
 49 3095903,3103013,3106013,3127213,3135313,3140413,3155513,3158513,
 50 3160613,3166613,3181813,3187813,3193913,3196913,3198913,3211123,
 51 3212123,3218123,3222223,3223223,3228223,3233323,3236323,3241423,
 52 3245423,3252523,3256523,3258523,3260623,3267623,3272723,3283823,
 53 3285823,3286823,3288823,3291923,3293923,3304033,3305033,3307033,
 54 3310133,3315133,3319133,3321233,3329233,3331333,3337333,3343433,
 55 3353533,3362633,3364633,3365633,3368633,3380833,3391933,3392933,
 56 3400043,3411143,3417143,3424243,3425243,3427243,3439343,3441443,
 57 3443443,3444443,3447443,3449443,3452543,3460643,3466643,3470743,
 58 3479743,3485843,3487843,3503053,3515153,3517153,3528253,3541453,
 59 3553553,3558553,3563653,3569653,3586853,3589853,3590953,3591953,
 60 3594953,3601063,3607063,3618163,3621263,3627263,3635363,3643463,
 61 3646463,3670763,3673763,3680863,3689863,3698963,3708073,3709073,
 62 3716173,3717173,3721273,3722273,3728273,3732373,3743473,3746473,
 63 3762673,3763673,3765673,3768673,3769673,3773773,3774773,3781873,
 64 3784873,3792973,3793973,3799973,3804083,3806083,3812183,3814183,
 65 3826283,3829283,3836383,3842483,3853583,3858583,3863683,3864683,
 66 3867683,3869683,3871783,3878783,3893983,3899983,3913193,3916193,
 67 3918193,3924293,3927293,3931393,3938393,3942493,3946493,3948493,
 68 3964693,3970793,3983893,3991993,3994993,3997993,3998993,7014107,
 69 7035307,7036307,7041407,7046407,7057507,7065607,7069607,7073707,
 70 7079707,7082807,7084807,7087807,7093907,7096907,7100017,7114117,
 71 7115117,7118117,7129217,7134317,7136317,7141417,7145417,7155517,
 72 7156517,7158517,7159517,7177717,7190917,7194917,7215127,7226227,
 73 7246427,7249427,7250527,7256527,7257527,7261627,7267627,7276727,
 74 7278727,7291927,7300037,7302037,7310137,7314137,7324237,7327237,
 75 7347437,7352537,7354537,7362637,7365637,7381837,7388837,7392937,
 76 7401047,7403047,7409047,7415147,7434347,7436347,7439347,7452547,
 77 7461647,7466647,7472747,7475747,7485847,7486847,7489847,7493947,
 78 7507057,7508057,7518157,7519157,7521257,7527257,7540457,7562657,
 79 7564657,7576757,7586857,7592957,7594957,7600067,7611167,7619167,
 80 7622267,7630367,7632367,7644467,7654567,7662667,7665667,7666667,
 81 7668667,7669667,7674767,7681867,7690967,7693967,7696967,7715177,
 82 7718177,7722277,7729277,7733377,7742477,7747477,7750577,7758577,
 83 7764677,7772777,7774777,7778777,7782877,7783877,7791977,7794977,
 84 7807087,7819187,7820287,7821287,7831387,7832387,7838387,7843487,
 85 7850587,7856587,7865687,7867687,7868687,7873787,7884887,7891987,
 86 7897987,7913197,7916197,7930397,7933397,7935397,7938397,7941497,
 87 7943497,7949497,7957597,7958597,7960697,7977797,7984897,7985897,
 88 7987897,7996997,9002009,9015109,9024209,9037309,9042409,9043409,
 89 9045409,9046409,9049409,9067609,9073709,9076709,9078709,9091909,
 90 9095909,9103019,9109019,9110119,9127219,9128219,9136319,9149419,
 91 9169619,9173719,9174719,9179719,9185819,9196919,9199919,9200029,
 92 9209029,9212129,9217129,9222229,9223229,9230329,9231329,9255529,
 93 9269629,9271729,9277729,9280829,9286829,9289829,9318139,9320239,
 94 9324239,9329239,9332339,9338339,9351539,9357539,9375739,9384839,
 95 9397939,9400049,9414149,9419149,9433349,9439349,9440449,9446449,
 96 9451549,9470749,9477749,9492949,9493949,9495949,9504059,9514159,
 97 9526259,9529259,9547459,9556559,9558559,9561659,9577759,9583859,
 98 9585859,9586859,9601069,9602069,9604069,9610169,9620269,9624269,
 99 9626269,9632369,9634369,9645469,9650569,9657569,9670769,9686869,
100 9700079,9709079,9711179,9714179,9724279,9727279,9732379,9733379,
101 9743479,9749479,9752579,9754579,9758579,9762679,9770779,9776779,
102 9779779,9781879,9782879,9787879,9788879,9795979,9801089,9807089,
103 9809089,9817189,9818189,9820289,9822289,9836389,9837389,9845489,
104 9852589,9871789,9888889,9889889,9896989,9902099,9907099,9908099,
105 9916199,9918199,9919199,9921299,9923299,9926299,9927299,9931399,
106 9932399,9935399,9938399,9957599,9965699,9978799,9980899,9981899,
107 9989899,
108 };
109 
110 int main()
111 {
112     __int64 a,b;
113     int i,j;
114     while(~scanf("%I64d%I64d",&a,&b))
115     {
116         for(i=0;num[i]<=9989899;i++)
117         {
118             if(num[i]>=a)
119                 break;
120         }
121         for(j=i;num[j]<=9989899;j++)
122         {
123             if(num[j]<=b&&num[j]!=0)
124                 printf("%I64d\n",num[j]);
125             else
126                 break;
127         }
128         printf("\n");
129     }
130     return 0;
131 }
132 
133 
134 /*    普通素数筛选法
135 bool prime[100000003];
136 void isprime()
137 {
138     __int64 i,j;
139     memset(prime,0,sizeof(prime));
140     for(i=2;i<=100000001;i++)
141     {
142         if(!prime[i])
143             for(j=i*i;j<=100000001;j+=i)
144                 prime[j]=1;
145     }
146 }
147 */
148 /*
149 int main()
150 {
151     __int64 a,b;
152     __int64 i;
153     isprime();
154     int cnt=0;
155     while(~scanf("%I64d%I64d",&a,&b))
156     {
157         for(i=11;i<=100000001;i++)
158         {
159             if(!prime[i])
160             {
161                 
162                 char str[10];
163                 ltoa(i,str,10);
164                 int len=strlen(str);
165                 bool flag=true;
166                 for(int j=0;j<len;j++)
167                 {
168                     if(str[len-j-1]!=str[j])
169                     {
170                         flag=false;
171                         break;
172                     }
173                 }
174                 if(flag)
175                 {
176                     printf("%I64d,",i);
177                     cnt++;
178                     if(cnt%8==0)
179                     printf("\n");
180                 }                
181             }
182         }
183     }
184     return 0;
185 }*/

注意：

1、普通素数打表方法

2、ltoa函数将长整形转换成字符数组

函数介绍：

void Format( LPCTSTR lpszFormat, ... );和printf的使方法一样

void Format( UINT nFormatID, ... );利用资源格式化字符串,这个比上面的省空间,方便改,功能一样

作用:像printf一样格式化字符串

int sprintf( char *buffer, const char *format [, argument] ... );//用法和 printf 一样

char *itoa( int value, char *string, int radix );

注:

参数:int value :是要转为字符串的int型

char *string :存放字符串的缓冲区

int radix :将int转换为多少进制的数存放在缓冲区中

char *ltoa( long value, char *string, int radix );

注:

参数:long value:是要转为字符串的long型

char *string :存放字符串的缓冲区

int radix :将long转换为多少进制的数存放在缓冲区中

char *ultoa( unsigned long value, char *string, int radix );

注:

参数:unsigned long value:是要转为字符串的unsigned long型

char *string :存放字符串的缓冲区

int radix :将unsigned long转换为多少进制的数存放在缓冲区中

int atoi( const char *string );

注:

参数:const char *string :是要转为int型的字符串

返回值:字符串对应的int型

long atol( const char *string );

注:

参数:const char *string :是要转为long型的字符串

返回值:字符串对应的long型

double atof( const char *string );

注:

参数:const char *string :是要转为double型的字符串

返回值:字符串对应的double型

例:

1.void Format( LPCTSTR lpszFormat, ... );

CString a,b;
a = "12卡拉";

b.Format("%s", a); // b的值为"12卡拉";,因为是把a格式化到b中,相当于a=b
b.Format("%d", a.GetLength()); // b的值为6,因为是把a的字节长格式化到b中

2.void Format( UINT nFormatID, ... );

(1)先打开"ResourceView"视窗

(2)点开"String Table"

(3)双击"String Table [English [U.S.]]"

(4)右键右边的下边空白,点"New String"

(5)在"Caption"右边的框中添:%d(这里也可以改成%s,%c等,根据须要来决定)

(6)把上面的"ID"记住

CString a,b;
a = "12卡拉";
b.Format(添上面的ID号, a.GetLength()); // b的值为6,因为是把a的字节长格式化到b中

例2:

char *p = new char[255];
int a = 10;
double b = 3.14;
long c = 20;
unsigned d = 30;
char *e = "abcde";
CString f;

sprintf(p, "%d", a);   //p中的值为10
sprintf(p, "%lf", b); //p中的值为3.140000
sprintf(p, "%ld", c); //p中的值为20
sprintf(p, "%u", d);   //p中的值为30
sprintf(p, "%s", e);   //p中的值为abcde

f.Format("%d", a);   //f中的值为10
f.Format("%lf", b); //f中的值为3.140000
f.Format("%ld", c); //f中的值为20
f.Format("%u", d);   //f中的值为30
f.Format("%s", e);   //f中的值为abcde

itoa(a, p, 10);      //p中的值为10
ltoa(c, p, 10);      //p中的值为20
ultoa(d, p, 10);     //p中的值为30

char *g = "40";
char *h = "4.59";
int i = atoi(g); //i中的值为40
long j = atol(g); //j中的值为40
double k = atof(h); //k中的值为4.58999999...