UVa 123 Searching Quickly

#include <iostream>#include <cstdio>#include <cstring>#include <string>#include <cctype>#include <cstdlib>using namespace std;struct key{    char keywords[100]; //关键字    int line; //所在行    int start; //行偏移位置};key keys[3000];int num_key = 0;char ignore[60][15];int num_ig = 0;char titles[250][300];int num_tit = 0;//qsort使用的比较函数int cmp_key(const void *a, const void *b) {    key *_a = (key *)a;    key *_b = (key *)b;    int ret = strcmp(_a->keywords, _b->keywords);    if(ret == 0) {        if(_a->line == _b->line) {            return _a->start - _b->start;        } else {            return _a->line - _b->line;        }    } else {        return ret;    }}// tilte转换为小写void titles_lower(){    for(int i=0; i<num_tit; i++) {        char *p = titles[i];        while(*p) {            *p = tolower(*p);            p++;        }    }}// 判断关键字是否在ignore中bool in_ignore(const char *words) {    for(int i=0; i<num_ig; i++) {        if(strcmp(words, ignore[i]) == 0) return true;    }    return false;}int main(){    #ifndef ONLINE_JUDGE    freopen("in.txt", "r", stdin);    #endif    while(gets(ignore[num_ig])) {        if(ignore[num_ig][0] == ':') break;        else num_ig++;    }    //for(int i=0; i<num_ig; i++) puts(ignore[i]);    while(gets(titles[num_tit++]));    titles_lower();    //for(int i=0; i<num_tit; i++) puts(titles[i]);    key k;    char *p;    for(int i=0; i<num_tit; i++) { //获得keyword        p = titles[i];        while(sscanf(p, "%s", k.keywords) == 1) {            if(!in_ignore(k.keywords)) {                k.line = i;                k.start = p-titles[i];                keys[num_key++] = k;            }            p += strlen(k.keywords);            while(*p == ' ') p++; //排除空格        }    }    qsort(keys, num_key, sizeof(key), cmp_key); // keyword排序    char buff[300];    for(int i=0; i<num_key; i++) {        strcpy(buff, titles[keys[i].line]);        p = buff + keys[i].start;        char *q = p + strlen(keys[i].keywords);        while(p<q) {            *p = toupper(*p);            p++;        }        puts(buff);    }    return 0;}