SRM 393(1-250pt)

题意：有m个人投票，每个人在心里对所有候选者排了一个序，比如“210”，则他最想投2号，如果2号已经出局他会投1号，最后投0号，否则弃权不投。选举时进行多轮投票，知道选出winner或者所有人均出局。每轮投票以后，得票最高者所得票数如果严格大于该轮投票人数的50%，则他成为winner，游戏结束；若不大于50%，则将得票最低的人淘汰，如果有多人得票相同且最低，则一起淘汰出局，然后进行下一轮投票。

解法：纯模拟。不过题意很不清晰，有两个地方我都弄了半天猜弄懂。。。就当学习官方题解的代码了。

tag:simulation

// BEGIN CUT HERE
/*
 * Author:  plum rain
 * score :
 */
/*

 */
// END CUT HERE
#line 11 "InstantRunoffVoting.cpp"
#include <sstream>
#include <stdexcept>
#include <functional>
#include <iomanip>
#include <numeric>
#include <fstream>
#include <cctype>
#include <iostream>
#include <cstdio>
#include <vector>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <set>
#include <queue>
#include <bitset>
#include <list>
#include <string>
#include <utility>
#include <map>
#include <ctime>
#include <stack>

using namespace std;

#define clr0(x) memset(x, 0, sizeof(x))
#define clr1(x) memset(x, -1, sizeof(x))
#define pb push_back
#define mp make_pair
#define sz(v) ((int)(v).size())
#define all(t) t.begin(),t.end()
#define zero(x) (((x)>0?(x):-(x))<eps)
#define out(x) cout<<#x<<":"<<(x)<<endl
#define tst(a) cout<<a<<" "
#define tst1(a) cout<<#a<<endl
#define CINBEQUICKER std::ios::sync_with_stdio(false)

typedef vector<int> VI;
typedef vector<string> VS;
typedef vector<double> VD;
typedef pair<int, int> pii;
typedef long long int64;

const double eps = 1e-8;
const double PI = atan(1.0)*4;
const int inf = 2139062143 / 2;

bool vis[20];
int idx[50], num[20];
pii an[50];

bool cmp(pii a, pii b)
{
    return a.second < b.second;
}

class InstantRunoffVoting
{
    public:
        int winner(vector <string> v){
            clr0 (vis); clr0 (idx);
            int n = sz(v), m = sz(v[0]); 
            int cnt = 0;
            while (cnt < m){
                int tmp = n;
                clr0 (num);
                for (int i = 0; i < n; ++ i){
                    while (idx[i] < m && vis[v[i][idx[i]] - '0']) ++ idx[i];
                    if (idx[i] >= m){ 
                        -- tmp; continue;
                    }
                    ++ num[v[i][idx[i]] - '0'];
                }
                int all = 0;
                for (int i = 0; i < m; ++ i)
                    if(!vis[i]) an[all++] = mp(i, num[i]);
                sort(an, an+all, cmp);
                if (an[all-1].second * 2 > tmp) return an[all-1].first;

                for (int i = 0; i < all; ++ i){
                    if (an[i].second != an[0].second) break;
                    ++ cnt; vis[an[i].first] = 1;
                }
            }
            return -1;
        }
        
// BEGIN CUT HERE
    public:
    void run_test(int Case) { if ((Case == -1) || (Case == 0)) test_case_0(); if ((Case == -1) || (Case == 1)) test_case_1(); if ((Case == -1) || (Case == 2)) test_case_2(); if ((Case == -1) || (Case == 3)) test_case_3(); if ((Case == -1) || (Case == 4)) test_case_4(); if ((Case == -1) || (Case == 5)) test_case_5(); }
    private:
    template <typename T> string print_array(const vector<T> &V) { ostringstream os; os << "{ "; for (typename vector<T>::const_iterator iter = V.begin(); iter != V.end(); ++iter) os << '"' << *iter << "","; os << " }"; return os.str(); }
    void verify_case(int Case, const int &Expected, const int &Received) { cerr << "Test Case #" << Case << "..."; if (Expected == Received) cerr << "PASSED" << endl; else { cerr << "FAILED" << endl; cerr << "	Expected: "" << Expected << '"' << endl; cerr << "	Received: "" << Received << '"' << endl; } }
    void test_case_0() { string Arr0[] = {"01","10","01","01","10"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 0; verify_case(0, Arg1, winner(Arg0)); }
    void test_case_1() { string Arr0[] = {"120","102","210","021","012"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 1; verify_case(1, Arg1, winner(Arg0)); }
    void test_case_2() { string Arr0[] = {"10","01"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = -1; verify_case(2, Arg1, winner(Arg0)); }
    void test_case_3() { string Arr0[] = {"3120","3012","1032"
,"3120","2031","2103"
,"1230","1230"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = -1; verify_case(3, Arg1, winner(Arg0)); }
    void test_case_4() { string Arr0[] = {"24103","30412","32014","21043","30412"
,"32401","14203","04123","30241","02413"
,"13042","01432","01342","32401","24301"
,"12430","41023","02413","42310","12043"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 1; verify_case(4, Arg1, winner(Arg0)); }
    void test_case_5() { string Arr0[] = {"0649853172","2146875039","2671548309"
,"5897216403","4719823056","7945213860"
,"9021538647","9286145307","9176403528"
,"3709486152"}; vector <string> Arg0(Arr0, Arr0 + (sizeof(Arr0) / sizeof(Arr0[0]))); int Arg1 = 9; verify_case(5, Arg1, winner(Arg0)); }

// END CUT HERE

};

// BEGIN CUT HERE
int main()
{
//    freopen( "a.out" , "w" , stdout );    
    InstantRunoffVoting ___test;
    ___test.run_test(-1);
       return 0;
}
// END CUT HERE