HDU 5007 Post Robot KMP (ICPC西安赛区网络预选赛 1001)
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=5007
解题报告:输入一篇文章,从头开始,当遇到 “Apple”, “iPhone”, “iPod”, “iPad” 这几个字符串时,输出”MAI MAI MAI!“,当遇到"Sony"时,输出“SONY DAFA IS GOOD!"。
看题太渣,题目意思还有个每个单词最多只出现一次关键词。有了这个条件就简单了,只要分别对每个单词进行五次KMP,匹配到了就输出对应的解释。
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include<iostream> 2 #include<cstring> 3 #include<cstdio> 4 #include<algorithm> 5 using namespace std; 6 char str[1000000]; 7 int next[1000000]; 8 void get_next(char* s,int* next) 9 { 10 int len = strlen(s); 11 int i = -1,j = 0; 12 memset(next,0,sizeof(next)); 13 next[0] = 0; 14 while(j < len) 15 { 16 if(i < 0 || s[i] == s[j]) 17 { 18 i++; 19 next[j+1] = i; 20 } 21 else i = 0; 22 j++; 23 } 24 } 25 int kmp(char* s,char* t,int* next) 26 { 27 get_next(t,next); 28 int lens = strlen(s); 29 int lent = strlen(t); 30 int i = 0,j = 0; 31 while(i < lens && j < lent) 32 { 33 if(s[i] == t[j]) j++; 34 else j = next[j]; 35 i++; 36 // printf("%d %d\n",i,j); 37 } 38 if(j == lent) return i - lent; //匹配成功返回开始配对的位置 39 else return -1; //匹配失败,返回尾指针 40 } 41 char temp[6][20] = {"Apple","iPhone","iPod","iPad","Sony"}; 42 int main() 43 { 44 while(scanf("%s",str)!=EOF) 45 { 46 if(kmp(str,temp[0],next)!=-1) puts("MAI MAI MAI!"); 47 if(kmp(str,temp[1],next)!=-1) puts("MAI MAI MAI!"); 48 if(kmp(str,temp[2],next)!=-1) puts("MAI MAI MAI!"); 49 if(kmp(str,temp[3],next)!=-1) puts("MAI MAI MAI!"); 50 if(kmp(str,temp[4],next)!=-1) puts("SONY DAFA IS GOOD!"); 51 } 52 }