HDU 3720

    没什么好说的，最近太水，各种犯2...

#include <stdio.h>#include <stdlib.h>#include <math.h>#include <string.h>#include <string>#include <vector>#include <map>#include <set>#include <queue>#include <algorithm>#include <iostream>#include <sstream>using namespace std;const int inf = 1000000000;struct Player {    string name;    int ability;    string position;        bool operator < (const Player &oth) const {        return position < oth.position;    }} player[23];int additional[23][23];int find(const string &name) {    for (int i = 0; ; i++)        if (player[i].name == name) return i;}int pd, pg, pm, ps;     // 分别是第一个后卫、第一个守门员、第一个中场、第一个前锋在player中的位置。vector<int> select;int ans;void dfs(int x) {    if (select.size() >= 11) {        int tmp = 0;        for (int i = 0; i < 11; i++) {            tmp += player[select[i]].ability;            for (int j = i + 1; j < 11; j++)                tmp += additional[select[i]][select[j]];        }        if (tmp > ans) ans = tmp;        return;    }    if (x >= 23) return;    int y = x + 1;    if (select.size() >= 9) {        if (23 - y >= 11 - select.size()) dfs(y);   // 如果可以不选x        select.push_back(x);        if (select.size() == 11) y = 23;            // 如果选了x，已经有11人被选        dfs(y);        select.pop_back();    } else if (select.size() >= 5) {        if (ps - y >= 9 - select.size()) dfs(y);    // 如果可以不选x        select.push_back(x);        if (select.size() == 9) y = ps;             // 如果选了x，已经有9人被选(不需要中场了)        dfs(y);        select.pop_back();    } else if (select.size() >= 4) {        if (pm - y >= 5 - select.size()) dfs(y);    // 如果可以不选x        select.push_back(x);        if (select.size() == 5) y = pm;             // 如果选了x，已经有5人被选(不需要守门员了)        dfs(y);        select.pop_back();    } else {        if (pg - y >= 4 - select.size()) dfs(y);    // 如果可以不选x        select.push_back(x);        if (select.size() == 4) y = pg;             // 如果选了x，已经有4人被选(不需要后卫了)        dfs(y);        select.pop_back();    }}int main() {    int i, m, a, b, profit;    string namea, nameb;    while (cin >> player[0].name >> player[0].ability >> player[0].position) {        for (i = 1; i < 23; i++)            cin >> player[i].name >> player[i].ability >> player[i].position;        sort(player, player + 23);        cin >> m;        memset(additional, 0, sizeof(additional));        for (i = 0; i < m; i++) {            cin >> namea >> nameb >> profit;            a = find(namea);            b = find(nameb);            additional[a][b] =            additional[b][a] = profit;        }        pd = pg = pm = ps = -1;        for (i = 0; i < 23; i++) {            switch (player[i].position[0]) {            case 'd': if (pd == -1) pd = i; break;            case 'g': if (pg == -1) pg = i; break;            case 'm': if (pm == -1) pm = i; break;            case 's': if (ps == -1) ps = i; break;            }        }        if (pd == -1 || pg == -1 || pm == -1 || ps == -1 ||            pg - pd < 4 || pm - pg < 1 || ps - pm < 4 || 23 - ps < 2) {            cout << "impossible" << endl;            continue;        }        ans = -inf;        dfs(0);        cout << ans << endl;    }    return 0;}