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10123_PrimePalindromes

2022-5-16 18:16| 发布者: Hocassian| 查看: 81| 评论: 0|原作者: 肇庆学院ACM合集

摘要:

C:\Users\Administrator\Downloads\2019-10-12-10-14-3-89504575329899-Problem List-采集的数据-后羿采集器.html

Pro.ID

10123

Title

Prime Palindromes

Title链接

http://10.20.2.8/oj/exercise/problem?problem_id=10123

AC

105

Submit

370

Ratio

28.38%

时间&空间限制

Time Limit: 400/200 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)

描述

The number 151 is a prime palindrome because it is both a prime number and a palindrome (it is the same number when read forward as backward). Write a program that finds all prime palindromes in the range of two supplied numbers a and b ( 5 ≤ a < b ≤ 100000000 ); both a and b are considered to be within the range.

输入

Multiple test cases. Each case on one line:

Two integers, a and b

输出

Description

Input

Multiple test cases. Each case on one line:

Two integers, a and b

Output

For each case, output the list of palindromic primes in numerical order, one per line.

After each case, output one blank line.

Sample Input

5 500
750 14000

Sample Output

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

757
787
797
919
929
10301
10501
10601
11311
11411
12421
12721
12821
13331
13831
13931

Hint

Generate the palindromes and see if they are prime.

Generate palindromes by combining digits properly. You might need more than one of the loops like below.

/* generate five digit palindrome: */
for (d1 = 1; d1 <= 9; d1+=2) { /* only odd; evens aren't so prime */
for (d2 = 0; d2 <= 9; d2++) {
for (d3 = 0; d3 <= 9; d3++) {
palindrome = 10000*d1 + 1000*d2 +100*d3 + 10*d2 + d1;
... deal with palindrome ...
}
}
}

Source

USACO training course