原题: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=399
题目:
The Decoder
Write a complete program that will correctly decode a set of characters into a valid message. Your program should read a given file of a simple coded set of characters and print the exact message that the characters contain. The code key for this simple coding is a one for one character substitution based upon a single arithmetic manipulation of the printable portion of the ASCII character set.
Input and Output
For example: with the input file that contains:
1JKJ’pz’{ol’{yhklthyr’vm’{ol’Jvu{yvs’Kh{h’Jvywvyh{pvu5
1PIT’pz’h’{yhklthyr’vm’{ol’Pu{lyuh{pvuhs’I|zpulzz’Thjopul’Jvywvyh{pvu5
1KLJ’pz’{ol’{yhklthyr’vm’{ol’Kpnp{hs’Lx|pwtlu{‘Jvywvyh{pvu5
your program should print the message:
*CDC is the trademark of the Control Data Corporation.
*IBM is a trademark of the International Business Machine Corporation.
*DEC is the trademark of the Digital Equipment Corporation.
Your program should accept all sets of characters that use the same encoding scheme and should print the actual message of each set of characters.
Sample Input
1JKJ’pz’{ol’{yhklthyr’vm’{ol’Jvu{yvs’Kh{h’Jvywvyh{pvu5
1PIT’pz’h’{yhklthyr’vm’{ol’Pu{lyuh{pvuhs’I|zpulzz’Thjopul’Jvywvyh{pvu5
1KLJ’pz’{ol’{yhklthyr’vm’{ol’Kpnp{hs’Lx|pwtlu{‘Jvywvyh{pvu5
Sample Output
*CDC is the trademark of the Control Data Corporation.
*IBM is a trademark of the International Business Machine Corporation.
*DEC is the trademark of the Digital Equipment Corporation.
思路:
对于每一个字符,它变成Ascii减去一个常数的字符。讲一个字符串变成另一个字符串。
通过样例我们可以发现,任取两个字符,他们的ascii码的差值为7,所以只需要对读入的每个字符做一次减法即可。
代码:
#include <iostream>
#include"string.h"
#include"cstdio"
#include"stdlib.h"
#include"algorithm"
using namespace std;
int main()
{
char s[1000];
while(scanf("%s",s)!=EOF)
{
int l=strlen(s);
for(int i=0;i<l;i++)
{
s[i]=s[i]-7;
}
printf("%s\n",s);
}
return 0;
}