You are to find all the two-word compound words in a dictionary. A two-word compound word is a word in the dictionary that is the concatenation of exactly two other words in the dictionary. Input Standard input consists of a number of lowercase words, one per line, in alphabetical order. There will be no more than 120,000 words. Output Your output should contain all the compound words, one per line, in alphabetical order. Sample Input a alien born less lien never nevertheless new newborn the zebra Sample Output alien newborn
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<string>
using namespace std;
const int maxn=2e5;
int a[maxn], t = -1, sum = 0;
char s[maxn][30], ch1[30], ch2[30];
int Hash(char *str)
{
int seed = 31, hash = 0;
while (*str)
hash = hash * seed + *str++;
return hash & 0x7FFFFFFF;
}
int Find(int key, int l, int r)
{
int mid = (l + r) / 2;
if(l>r) return 0;
if(a[mid]==key) return 1;
else if(a[mid]>key) Find(key, l, mid - 1);
else Find(key, mid + 1, r);
}
int main()
{
int i, j, k, l;
while(gets(s[++t])) a[t] = Hash(s[t]);
sort(a, a + t);
for (i = 0; i<t; i++)
{
l = strlen(s[i]);
for (j = 0; j<l - 1; j++)
{
for (k = 0; k <= j; k++)
ch1[k] = s[i][k];
ch1[j + 1] = ' ';
for (k = j + 1; k<l; k++)
ch2[k - j - 1] = s[i][k];
ch2[l - j - 1] = ' ';
if (Find(Hash(ch1), 0, t - 1) + Find(Hash(ch2), 0, t - 1) == 2)
{
printf("%s
",s[i]);
break;
}
}
}
return 0;
}