第一次玩ACM。。。有点小紧张小兴奋。这题目好难啊，只是网赛就这么难。。。只把最简单的两题做出来了。

题目１：

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代码：

//#define _ACM_

#include<iostream>

#include<cstring>

#include<string>

#include<vector>

#include<map>

#include<set>

using namespace std;

char line[111], word[111];

int T(0);

struct CAT{

    //string N;         //name of current category

    map<string, CAT> C; //categorys

    set<string> B;      //books

    void show(const int sp) const{

        for (const auto &r : C) {

            for (int i = 0;i < sp;++i) printf("    ");

            printf("%s\n", r.first.c_str());

            r.second.show(sp+1);

        }

        for (const auto &r : B) {

            for (int i = 0;i < sp;++i) printf("    ");

            printf("%s\n", r.c_str());

        }

    }

};

int main()

{

#ifdef _ACM_

#define gets(T) gets_s(T, 111)

    freopen("in.txt", "r", stdin);

#endif

    while (gets(line)) {

        map<string, CAT> cat;

        do {

            CAT* pc(NULL);

            char *p(word);

            for (char *pl(line);*pl != '\0';++pl) {

                if (*pl != '/') *p++ = *pl;

                else {

                    *p = '\0';p = word;

                    if (pc == NULL) pc = &cat[word];

                    else pc = &(pc->C[word]);

                }

            }

            *p = '\0';

            pc->B.insert(word);

        } while (gets(line) && strcmp(line, "0"));

        printf("Case %d:\n", ++T);

        for (const auto &r : cat) {

            printf("%s\n", r.first.c_str());

            r.second.show(1);

        }

    }

    return 0;

}

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题目３：

---

代码：

//#define _ACM_

#include<iostream>

#include<string>

#include<map>

using namespace std;

inline bool isch(char c) { return c >= 'a' && c <= 'z'; }

char ch, line[555], word[555];

string pr;

map<string, unsigned> phs;

int main()

{

#ifdef _ACM_

#define gets(T) gets_s(T, 555)

    freopen("in.txt", "r", stdin);

#endif

    ch = getchar();

    while (true) {

        char *p(word);

        while (isch(ch)) {

            *p++ = ch;

            ch = getchar();

        }

        *p = '\0';

        bool ispunc(false);

        while (ch != EOF && !isch(ch) && ch != '#') {

            if (ch == ',' || ch == '.' || ch == '\n') ispunc = true;

            ch = getchar();

        }

        if (ch == EOF) break;//the end of test file

        else if (ch == '#') {//the end of current text

            if (!pr.empty()) ++phs[pr + ' ' + word];

            if (ispunc) pr.clear();

            else pr = word;

            unsigned maxu = 0;

            string maxs;

            for (const auto& r : phs)

                if (r.second > maxu) maxu = r.second, maxs = r.first;

            printf("%s:%u\n", maxs.c_str(), maxu);

            phs.clear(), pr.clear();

            getchar(), getchar(), getchar(), getchar();

            ch = getchar();

        }

        else {//find a word/phrase

            if (!pr.empty()) ++phs[pr + ' ' + word];

            if (ispunc) pr.clear();

            else pr = word;

        }

    }

    return 0;

}