UVa 10391 - Compound Words （字符串hash）

Compound Words

Time Limit:3000MS Memory Limit:Unknown 64bit IO Format:%lld & %llu

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Description

Problem E: Compound Words

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 theconcatenation 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, inalphabetical order.

Sample Input

aalienbornlesslienneverneverthelessnewnewbornthezebra

Sample Output

aliennewborn

题意：

给定一个字典，找出其中所有的复合词，即恰好由两个单词连接而成的单词。

思路：

先hash存下每个单词 然后枚举每个单词 对于单词i，枚举单词拆分的地方，然后看两个子单词有没有在字典里面

#include <cstdio>#include <iostream>#include <vector>#include <algorithm>#include <cstring>#include <string>#include <map>#include <cmath>#include <queue>#include <set>using namespace std;//#define WIN#ifdef WINtypedef __int64 LL;#define iform "%I64d"#define oform "%I64d\n"#define oform1 "%I64d"#elsetypedef long long LL;#define iform "%lld"#define oform "%lld\n"#define oform1 "%lld"#endif#define S64I(a) scanf(iform, &(a))#define P64I(a) printf(oform, (a))#define P64I1(a) printf(oform1, (a))#define REP(i, n) for(int (i)=0; (i)<n; (i)++)#define REP1(i, n) for(int (i)=1; (i)<=(n); (i)++)#define FOR(i, s, t) for(int (i)=(s); (i)<=(t); (i)++)const int INF = 0x3f3f3f3f;const double eps = 10e-9;const double PI = (4.0*atan(1.0));const int maxn = 120000 + 20;int Head[maxn];int Next[maxn];string data[maxn];int cnt;int ELFhash(char * s) {    unsigned long h = 0;    while(*s) {        h = (h << 4) + *s++;        unsigned long g = h & 0xf0000000L;        if(g) h ^= g >> 24;        h &= ~g;    }    return h % maxn;}void init() {    memset(Head, -1, sizeof(Head));    memset(Next, -1, sizeof(Next));    cnt = 0;}void insert(char * s) {    int key = ELFhash(s);    data[cnt] = string(s);    Next[cnt] = Head[key];    Head[key] = cnt;    cnt++;}bool find(char * s) {    int key = ELFhash(s);    int u = Head[key];    while(u != -1) {        if(strcmp(data[u].c_str(), s) == 0) return true;        u = Next[u];    }    return false;}void subString(char * sub, char * s, int st, int ed) {    int len = ed - st + 1;    for(int i=0; i<len; i++) {        sub[i] = s[st+i];    }    sub[len] = '\0';}char ins[maxn][100];char tmp1[100];char tmp2[100];int main() {    int n = 0;    init();    while(scanf("%s", ins[n]) != EOF) {        insert(ins[n++]);    }    for(int i=0; i<n; i++) {        int len = strlen(ins[i]);        for(int j=0; j<len-1; j++) {            subString(tmp1, ins[i], 0, j);            subString(tmp2, ins[i], j+1, len-1);            if(find(tmp1) && find(tmp2)) {                puts(ins[i]);                break;            }        }    }    return 0;}