• UVa 1009 Balloons in a Box


    方法:暴力 枚举

    数据量较小,可以枚举所有n!个order,然后依次计算该order所对应的体积,更新答案。因为没有剪枝,所以用next_permutation 列出所有可能性即可。

    code:

      1 #include <cstdio>
      2 #include <cstring>
      3 #include <algorithm>
      4 #include <iostream>
      5 #include <string>
      6 #include <vector>
      7 #include <stack>
      8 #include <bitset>
      9 #include <cstdlib>
     10 #include <cmath>
     11 #include <set>
     12 #include <list>
     13 #include <deque>
     14 #include <map>
     15 #include <queue>
     16 #include <fstream>
     17 #include <cassert>
     18 #include <unordered_map>
     19 #include <unordered_set>
     20 #include <cmath>
     21 #include <sstream>
     22 #include <time.h>
     23 #include <complex>
     24 #include <iomanip>
     25 #define Max(a,b) ((a)>(b)?(a):(b))
     26 #define Min(a,b) ((a)<(b)?(a):(b))
     27 #define FOR(a,b,c) for (ll (a)=(b);(a)<(c);++(a))
     28 #define FORN(a,b,c) for (ll (a)=(b);(a)<=(c);++(a))
     29 #define DFOR(a,b,c) for (ll (a)=(b);(a)>=(c);--(a))
     30 #define FORSQ(a,b,c) for (ll (a)=(b);(a)*(a)<=(c);++(a))
     31 #define FORC(a,b,c) for (char (a)=(b);(a)<=(c);++(a))
     32 #define FOREACH(a,b) for (auto &(a) : (b))
     33 #define rep(i,n) FOR(i,0,n)
     34 #define repn(i,n) FORN(i,1,n)
     35 #define drep(i,n) DFOR(i,n-1,0)
     36 #define drepn(i,n) DFOR(i,n,1)
     37 #define MAX(a,b) a = Max(a,b)
     38 #define MIN(a,b) a = Min(a,b)
     39 #define SQR(x) ((LL)(x) * (x))
     40 #define Reset(a,b) memset(a,b,sizeof(a))
     41 #define fi first
     42 #define se second
     43 #define mp make_pair
     44 #define pb push_back
     45 #define all(v) v.begin(),v.end()
     46 #define ALLA(arr,sz) arr,arr+sz
     47 #define SIZE(v) (int)v.size()
     48 #define SORT(v) sort(all(v))
     49 #define REVERSE(v) reverse(ALL(v))
     50 #define SORTA(arr,sz) sort(ALLA(arr,sz))
     51 #define REVERSEA(arr,sz) reverse(ALLA(arr,sz))
     52 #define PERMUTE next_permutation
     53 #define TC(t) while(t--)
     54 #define forever for(;;)
     55 #define PINF 1000000000000
     56 #define newline '
    '
     57 
     58 #define test if(1)if(0)cerr
     59 using namespace std;
     60 using namespace std;
     61 typedef vector<int> vi;
     62 typedef vector<vi> vvi;
     63 typedef pair<int,int> ii;
     64 typedef pair<double,double> dd;
     65 typedef pair<char,char> cc;
     66 typedef vector<ii> vii;
     67 typedef long long ll;
     68 typedef unsigned long long ull;
     69 typedef pair<ll, ll> l4;
     70 const double pi = acos(-1.0);
     71 
     72 struct Point
     73 {
     74     double x[3];
     75 };
     76 double distance(const Point &l, const Point &r)
     77 {
     78     double ret = 0;
     79     rep(i, 3)
     80     {
     81         double d = l.x[i]-r.x[i];
     82         ret += d*d;
     83     }
     84     return sqrt(ret);
     85 }
     86 Point v[2];
     87 Point center[6];
     88 double r[6];
     89 int perm[6] = {0,1,2,3,4,5};
     90 int n;
     91 double ans;
     92 void dfs(int pos, double vol)
     93 {
     94     int cur = perm[pos];
     95     if (pos == n)
     96     {
     97         ans = max(ans, vol);
     98         return;
     99     }
    100     double tmp = abs(v[0].x[0]-center[cur].x[0]);
    101     rep(i, 2) rep(j, 3)
    102     tmp = min(tmp, abs(v[i].x[j]-center[cur].x[j]));
    103     rep(i, pos)
    104     {
    105         if (!r[perm[i]]) continue;
    106         tmp = min(tmp, distance(center[perm[i]], center[cur])-r[perm[i]]);
    107     }
    108     if (tmp <= 0)
    109     {
    110         r[cur] = 0;
    111     }
    112     else
    113         r[cur] = tmp;
    114     dfs(pos+1, vol + pi * 4 / 3 * r[cur]*r[cur]*r[cur]);
    115 }
    116 int main()
    117 {
    118     ios::sync_with_stdio(false);
    119     cin.tie(0);
    120     int kase = 0;
    121     while (cin >> n && n)
    122     {
    123         
    124         rep(i, 2)
    125         rep(j, 3) cin >> v[i].x[j];
    126         rep(i, n)
    127         rep(j, 3) cin >> center[i].x[j];
    128         ans = 0;
    129         do
    130         {
    131             Reset(r, 0);
    132             dfs(0, 0);
    133         } while (next_permutation(perm, perm+n));
    134         double volume = 1;
    135         rep(i, 3) volume *= v[1].x[i]-v[0].x[i];
    136         volume = abs(volume);
    137         ans = volume-ans;
    138         cout << "Box " << ++kase << ": " << (int) (ans + 0.5) << newline << newline;;
    139     }
    140 
    141 }
    142 
    143 /*
    144  2
    145  0 0 0
    146  10 10 10 
    147  3 3 3 
    148  7 7 7
    149  0
    150 */
    View Code
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  • 原文地址:https://www.cnblogs.com/skyette/p/6360170.html
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