POJ 3096 surprising_string (coding with STL <map> )

[Description]:

The D-pairs of a string of letters are the ordered pairs of letters that are distance D from each other. A string is D-unique if all of its D-pairs are different. A string is surprising if it is D-unique for every possible distance D.

Consider the string ZGBG. Its 0-pairs are ZG, GB, and BG. Since these three pairs are all different, ZGBG is 0-unique. Similarly, the 1-pairs of ZGBG are ZB and GG, and since these two pairs are different, ZGBG is 1-unique. Finally, the only 2-pair of ZGBG is ZG, so ZGBG is 2-unique. Thus ZGBG is surprising. (Note that the fact that ZG is both a 0-pair and a 2-pair of ZGBG is irrelevant, because 0 and 2 are different distances.)

Acknowledgement: This problem is inspired by the "Puzzling Adventures" column in the December 2003 issue of Scientific American.

[Input]:

The input consists of one or more nonempty strings of at most 79 uppercase letters, each string on a line by itself, followed by a line containing only an asterisk that signals the end of the input.

[Output]:

For each string of letters, output whether or not it is surprising using the exact output format shown below.

[Sample Input]:

ZGBGXEEAABAABAAABBBCBABCC*

[Sample Output]:

ZGBG is surprising.X is surprising.EE is surprising.AAB is surprising.AABA is surprising.AABB is NOT surprising.BCBABCC is NOT surprising

解题思想：从要求来看，即定义D-pairs表示取字符串s中相距为D的两个字母所构成的字母对，该字母对中两个字母的位置顺序与他们在主串s中的位置顺序一致定义D-unique表示，若从字符串s中取出所有相距为D的字母对D-pairs，且这些D-pairs都是独一无二的，那么成字符串s是一个D-unique串D的取值范围为0~s.len()-2。然后这个用map的键值对来标记结果检测时更为方便。当然C的flag标记方式也可以，总的来说在大神看来是道简单的poj题目。

souce_code: 

/* * ===================================================================================== * *       Filename:  surprising_string.cpp *        Version:  1.0 *        Created:  2013年10月13日 19时13分54秒 *       Revision:  none *       Compiler:  g++ *         Author:  szm * * ===================================================================================== */#include <iostream>#include <string>#include <map>int main(int argc, char *argv[]){std::string s;while(std::getline(std::cin,s) && (s.c_str())[0]!='*'){if(s.size()<=2){std::cout<<s.c_str()<<" is surprising."<<std::endl;continue;}bool flag_final=true;for(int i=0;i<=(s.size()-2);i++){std::map<std::string,bool> mark;bool flag_unique=true;for(int j=0;j<=(s.size()-i-2);j++){char m_pair[3]={(s.c_str())[j],(s.c_str())[j+1+i],'\0'};std::string str(m_pair);if(!mark[str])      mark[str]=true;else{flag_unique=false;break;}}if(!flag_unique){flag_final=false;break;}mark.clear();}if(flag_final)      std::cout<<s<<" is surprising !"<<std::endl;else      std::cout<<s<<" is not surprising !"<<std::endl;}return 0;}