4N - 素数回文

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<string.h>
 4 char num[100000001];
 5 int palindrome(char str[])
 6 {
 7     int i, len, flag=1;
 8     len=strlen(str);
 9     for(i=0;i<len/2;i++)
10         if(str[i]!=str[len-1-i])
11         { flag=0; break; }
12     return flag;
13 }
14 
15 int prime(int n)
16 {
17     int i, flag=1;
18     for(i=2; i<n; i++)
19         if(n%i==0)
20         { flag=0; break; }
21     return flag;
22 }
23 
24 int main()
25 {
26     int a, b, i;
27     while(scanf("%d %d", &a, &b)!=EOF)
28     {
29         for(i=a;i<=b;i++)
30             if(prime(i))
31             {
32                 itoa(i,num,10);
33                 if(palindrome(num))
34                     puts(num);
35             }
36         printf("\n");
37     }
38     return 0;
39 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<math.h>
 4 #include<string.h>
 5 char num[100000001];
 6 int palindrome(char str[])
 7 {
 8     int i, len, flag=1;
 9     len=strlen(str);
10     for(i=0;i<len/2;i++)
11         if(str[i]!=str[len-1-i])
12         { flag=0; break; }
13     return flag;
14 }
15 
16 int prime(int n)
17 {
18     int i, flag=1, k;
19     k=(int)ceil(sqrt(n*1.0));
20     for(i=2; i<=k; i++)
21         if(n%i==0)
22         { flag=0; break; }
23     return flag;
24 }
25 
26 int main()
27 {
28     int a, b, i;
29     while(scanf("%d %d", &a, &b)!=EOF)
30     {
31         for(i=a;i<=b;i++)
32             if(prime(i))
33             {
34                 itoa(i,num,10);
35                 if(palindrome(num))
36                     puts(num);
37             }
38         printf("\n");
39     }
40     return 0;
41 }

 1 #include<stdio.h>
 2 int palindrome(int x)
 3 {
 4     int i=x, j=0, flag=0;
 5     while(i)
 6     { j=j*10+i%10; i/=10; }
 7     if(j==x) flag=1;
 8     return flag;
 9 }
10 
11 int prime(int n)
12 {
13     int i, flag=1, k;
14     if(n!=2&&n%2==0) flag=0;
15     else
16     {
17         for(i=2; i*i<=n; i++)
18             if(n%i==0)
19             { flag=0; break; }
20     }
21     return flag;
22 }
23 
24 int main()
25 {
26     int a, b, i;
27     while(scanf("%d %d", &a, &b)!=EOF)
28     {
29         for(i=a;i<=b;i++)
30             if(prime(i))
31                 if(palindrome(i))
32                     printf("%d\n", i);
33         printf("\n");
34     }
35     return 0;
36 }

 1 #include<stdio.h>
 2 int palindrome(int x)
 3 {
 4     int i=x, j=0, flag=0;
 5     while(i)
 6     { j=j*10+i%10; i/=10; }
 7     if(j==x) flag=1;
 8     return flag;
 9 }
10 
11 int prime(int n)
12 {
13     int i, flag=1;
14     for(i=3; i*i<=n; i++)
15         if(n%i==0)
16         { flag=0; break; }
17     return flag;
18 }
19 
20 int main()
21 {
22     int a, b, i;
23     while(scanf("%d %d", &a, &b)!=EOF)
24     {
25         for(i=a%2?a:a+1;i<=b&&i<=9989899;i+=2)
26         {
27             if(i>11&&i<100 || i>=1000&&i<10000 || i>=100000&&i<1000000)
28                 continue;
29             if(prime(i)&&palindrome(i))
30                 printf("%d\n", i);
31         }
32         printf("\n");
33     }
34     return 0;
35 }

 1 #include<stdio.h>
 2 #include<process.h>
 3 
 4 int palindrome(int x)
 5 {
 6     int i=x, j=0, flag=0;
 7     while(i)
 8     { j=j*10+i%10; i/=10; }
 9     if(j==x) flag=1;
10     return flag;
11 }
12 
13 int prime(int n)
14 {
15     int i, flag=1;
16     for(i=2; i*i<=n; i++)
17         if(n%i==0)
18         { flag=0; break; }
19     return flag;
20 }
21 
22 int main()
23 {
24     FILE *fp;
25     if((fp=fopen("Ntest.txt","wt"))==NULL)
26     {
27         printf("Error!\n");
28         exit(0);
29     }
30     int j=0;
31     for(int i=5;i<=100000000;i++)
32         if(prime(i)&&palindrome(i))
33         {
34             j++;
35             if(j%5) fprintf(fp, "%d, ", i);
36             else    fprintf(fp, "%d, \n", i);    
37         }
38     fprintf(fp, "\n\n%d", j);
39     printf("Done!\n");
40     fclose(fp);
41     return 0;
42 }

  1 #include<stdio.h>
  2 #define N 779
  3 
  4 int table[N]=
  5 {
  6 5, 7, 11, 101, 131, 
  7 151, 181, 191, 313, 353, 
  8 373, 383, 727, 757, 787, 
  9 797, 919, 929, 10301, 10501, 
 10 10601, 11311, 11411, 12421, 12721, 
 11 12821, 13331, 13831, 13931, 14341, 
 12 14741, 15451, 15551, 16061, 16361, 
 13 16561, 16661, 17471, 17971, 18181, 
 14 18481, 19391, 19891, 19991, 30103, 
 15 30203, 30403, 30703, 30803, 31013, 
 16 31513, 32323, 32423, 33533, 34543, 
 17 34843, 35053, 35153, 35353, 35753, 
 18 36263, 36563, 37273, 37573, 38083, 
 19 38183, 38783, 39293, 70207, 70507, 
 20 70607, 71317, 71917, 72227, 72727, 
 21 73037, 73237, 73637, 74047, 74747, 
 22 75557, 76367, 76667, 77377, 77477, 
 23 77977, 78487, 78787, 78887, 79397, 
 24 79697, 79997, 90709, 91019, 93139, 
 25 93239, 93739, 94049, 94349, 94649, 
 26 94849, 94949, 95959, 96269, 96469, 
 27 96769, 97379, 97579, 97879, 98389, 
 28 98689, 1003001, 1008001, 1022201, 1028201, 
 29 1035301, 1043401, 1055501, 1062601, 1065601, 
 30 1074701, 1082801, 1085801, 1092901, 1093901, 
 31 1114111, 1117111, 1120211, 1123211, 1126211, 
 32 1129211, 1134311, 1145411, 1150511, 1153511, 
 33 1160611, 1163611, 1175711, 1177711, 1178711, 
 34 1180811, 1183811, 1186811, 1190911, 1193911, 
 35 1196911, 1201021, 1208021, 1212121, 1215121, 
 36 1218121, 1221221, 1235321, 1242421, 1243421, 
 37 1245421, 1250521, 1253521, 1257521, 1262621, 
 38 1268621, 1273721, 1276721, 1278721, 1280821, 
 39 1281821, 1286821, 1287821, 1300031, 1303031, 
 40 1311131, 1317131, 1327231, 1328231, 1333331, 
 41 1335331, 1338331, 1343431, 1360631, 1362631, 
 42 1363631, 1371731, 1374731, 1390931, 1407041, 
 43 1409041, 1411141, 1412141, 1422241, 1437341, 
 44 1444441, 1447441, 1452541, 1456541, 1461641, 
 45 1463641, 1464641, 1469641, 1486841, 1489841, 
 46 1490941, 1496941, 1508051, 1513151, 1520251, 
 47 1532351, 1535351, 1542451, 1548451, 1550551, 
 48 1551551, 1556551, 1557551, 1565651, 1572751, 
 49 1579751, 1580851, 1583851, 1589851, 1594951, 
 50 1597951, 1598951, 1600061, 1609061, 1611161, 
 51 1616161, 1628261, 1630361, 1633361, 1640461, 
 52 1643461, 1646461, 1654561, 1657561, 1658561, 
 53 1660661, 1670761, 1684861, 1685861, 1688861, 
 54 1695961, 1703071, 1707071, 1712171, 1714171, 
 55 1730371, 1734371, 1737371, 1748471, 1755571, 
 56 1761671, 1764671, 1777771, 1793971, 1802081, 
 57 1805081, 1820281, 1823281, 1824281, 1826281, 
 58 1829281, 1831381, 1832381, 1842481, 1851581, 
 59 1853581, 1856581, 1865681, 1876781, 1878781, 
 60 1879781, 1880881, 1881881, 1883881, 1884881, 
 61 1895981, 1903091, 1908091, 1909091, 1917191, 
 62 1924291, 1930391, 1936391, 1941491, 1951591, 
 63 1952591, 1957591, 1958591, 1963691, 1968691, 
 64 1969691, 1970791, 1976791, 1981891, 1982891, 
 65 1984891, 1987891, 1988891, 1993991, 1995991, 
 66 1998991, 3001003, 3002003, 3007003, 3016103, 
 67 3026203, 3064603, 3065603, 3072703, 3073703, 
 68 3075703, 3083803, 3089803, 3091903, 3095903, 
 69 3103013, 3106013, 3127213, 3135313, 3140413, 
 70 3155513, 3158513, 3160613, 3166613, 3181813, 
 71 3187813, 3193913, 3196913, 3198913, 3211123, 
 72 3212123, 3218123, 3222223, 3223223, 3228223, 
 73 3233323, 3236323, 3241423, 3245423, 3252523, 
 74 3256523, 3258523, 3260623, 3267623, 3272723, 
 75 3283823, 3285823, 3286823, 3288823, 3291923, 
 76 3293923, 3304033, 3305033, 3307033, 3310133, 
 77 3315133, 3319133, 3321233, 3329233, 3331333, 
 78 3337333, 3343433, 3353533, 3362633, 3364633, 
 79 3365633, 3368633, 3380833, 3391933, 3392933, 
 80 3400043, 3411143, 3417143, 3424243, 3425243, 
 81 3427243, 3439343, 3441443, 3443443, 3444443, 
 82 3447443, 3449443, 3452543, 3460643, 3466643, 
 83 3470743, 3479743, 3485843, 3487843, 3503053, 
 84 3515153, 3517153, 3528253, 3541453, 3553553, 
 85 3558553, 3563653, 3569653, 3586853, 3589853, 
 86 3590953, 3591953, 3594953, 3601063, 3607063, 
 87 3618163, 3621263, 3627263, 3635363, 3643463, 
 88 3646463, 3670763, 3673763, 3680863, 3689863, 
 89 3698963, 3708073, 3709073, 3716173, 3717173, 
 90 3721273, 3722273, 3728273, 3732373, 3743473, 
 91 3746473, 3762673, 3763673, 3765673, 3768673, 
 92 3769673, 3773773, 3774773, 3781873, 3784873, 
 93 3792973, 3793973, 3799973, 3804083, 3806083, 
 94 3812183, 3814183, 3826283, 3829283, 3836383, 
 95 3842483, 3853583, 3858583, 3863683, 3864683, 
 96 3867683, 3869683, 3871783, 3878783, 3893983, 
 97 3899983, 3913193, 3916193, 3918193, 3924293, 
 98 3927293, 3931393, 3938393, 3942493, 3946493, 
 99 3948493, 3964693, 3970793, 3983893, 3991993, 
100 3994993, 3997993, 3998993, 7014107, 7035307, 
101 7036307, 7041407, 7046407, 7057507, 7065607, 
102 7069607, 7073707, 7079707, 7082807, 7084807, 
103 7087807, 7093907, 7096907, 7100017, 7114117, 
104 7115117, 7118117, 7129217, 7134317, 7136317, 
105 7141417, 7145417, 7155517, 7156517, 7158517, 
106 7159517, 7177717, 7190917, 7194917, 7215127, 
107 7226227, 7246427, 7249427, 7250527, 7256527, 
108 7257527, 7261627, 7267627, 7276727, 7278727, 
109 7291927, 7300037, 7302037, 7310137, 7314137, 
110 7324237, 7327237, 7347437, 7352537, 7354537, 
111 7362637, 7365637, 7381837, 7388837, 7392937, 
112 7401047, 7403047, 7409047, 7415147, 7434347, 
113 7436347, 7439347, 7452547, 7461647, 7466647, 
114 7472747, 7475747, 7485847, 7486847, 7489847, 
115 7493947, 7507057, 7508057, 7518157, 7519157, 
116 7521257, 7527257, 7540457, 7562657, 7564657, 
117 7576757, 7586857, 7592957, 7594957, 7600067, 
118 7611167, 7619167, 7622267, 7630367, 7632367, 
119 7644467, 7654567, 7662667, 7665667, 7666667, 
120 7668667, 7669667, 7674767, 7681867, 7690967, 
121 7693967, 7696967, 7715177, 7718177, 7722277, 
122 7729277, 7733377, 7742477, 7747477, 7750577, 
123 7758577, 7764677, 7772777, 7774777, 7778777, 
124 7782877, 7783877, 7791977, 7794977, 7807087, 
125 7819187, 7820287, 7821287, 7831387, 7832387, 
126 7838387, 7843487, 7850587, 7856587, 7865687, 
127 7867687, 7868687, 7873787, 7884887, 7891987, 
128 7897987, 7913197, 7916197, 7930397, 7933397, 
129 7935397, 7938397, 7941497, 7943497, 7949497, 
130 7957597, 7958597, 7960697, 7977797, 7984897, 
131 7985897, 7987897, 7996997, 9002009, 9015109, 
132 9024209, 9037309, 9042409, 9043409, 9045409, 
133 9046409, 9049409, 9067609, 9073709, 9076709, 
134 9078709, 9091909, 9095909, 9103019, 9109019, 
135 9110119, 9127219, 9128219, 9136319, 9149419, 
136 9169619, 9173719, 9174719, 9179719, 9185819, 
137 9196919, 9199919, 9200029, 9209029, 9212129, 
138 9217129, 9222229, 9223229, 9230329, 9231329, 
139 9255529, 9269629, 9271729, 9277729, 9280829, 
140 9286829, 9289829, 9318139, 9320239, 9324239, 
141 9329239, 9332339, 9338339, 9351539, 9357539, 
142 9375739, 9384839, 9397939, 9400049, 9414149, 
143 9419149, 9433349, 9439349, 9440449, 9446449, 
144 9451549, 9470749, 9477749, 9492949, 9493949, 
145 9495949, 9504059, 9514159, 9526259, 9529259, 
146 9547459, 9556559, 9558559, 9561659, 9577759, 
147 9583859, 9585859, 9586859, 9601069, 9602069, 
148 9604069, 9610169, 9620269, 9624269, 9626269, 
149 9632369, 9634369, 9645469, 9650569, 9657569, 
150 9670769, 9686869, 9700079, 9709079, 9711179, 
151 9714179, 9724279, 9727279, 9732379, 9733379, 
152 9743479, 9749479, 9752579, 9754579, 9758579, 
153 9762679, 9770779, 9776779, 9779779, 9781879, 
154 9782879, 9787879, 9788879, 9795979, 9801089, 
155 9807089, 9809089, 9817189, 9818189, 9820289, 
156 9822289, 9836389, 9837389, 9845489, 9852589, 
157 9871789, 9888889, 9889889, 9896989, 9902099, 
158 9907099, 9908099, 9916199, 9918199, 9919199, 
159 9921299, 9923299, 9926299, 9927299, 9931399, 
160 9932399, 9935399, 9938399, 9957599, 9965699, 
161 9978799, 9980899, 9981899, 9989899
162 };
163 
164 int main()
165 {
166     int a, b, i;
167     while(scanf("%d %d", &a, &b)!=EOF)
168     {
169         for(i=0;i<N;i++)
170             if(table[i]>=a&&table[i]<=b)
171                 printf("%d\n", table[i]);
172         printf("\n");
173     }
174     return 0;
175 }