SRM 395(1-250pt)

DIV1 250pt

题意：在平面直角坐标系中，只能走到整点，每次有两种移动方法，可以沿平行于坐标轴方向走，也可以沿45度方向走，前者走一步耗时wt，后者走一步耗时st。比如从(x, y)可以走到(x+1, y)，(x-1, y)，(x, y+1)，(x, y-1)四个点，耗时均为wt，也可以走到(x-1, y+1)，(x-1, y-1)，(x+1, y+1)，(x+1, y-1)，耗时均为st。给定x, y, wt, st，求从(0, 0)到(x, y)最少耗时多少。

解法：水题，见代码。

tag: greedy

 1 // BEGIN CUT HERE
 2 /*
 3 
 4 */
 5 // END CUT HERE
 6 #line 7 "StreetWalking.cpp"
 7 #include <cstdlib>
 8 #include <cctype>
 9 #include <cstring>
10 #include <cstdio>
11 #include <cmath>
12 #include <algorithm>
13 #include <vector>
14 #include <iostream>
15 #include <sstream>
16 #include <set>
17 #include <queue>
18 #include <fstream>
19 #include <numeric>
20 #include <iomanip>
21 #include <bitset>
22 #include <list>
23 #include <stdexcept>
24 #include <functional>
25 #include <string>
26 #include <utility>
27 #include <map>
28 #include <ctime>
29 #include <stack>
30 
31 using namespace std;
32 
33 #define clr0(x) memset(x, 0, sizeof(x))
34 #define clr1(x) memset(x, -1, sizeof(x))
35 #define pb push_back
36 #define mp make_pair
37 #define sz(v) ((int)(v).size())
38 #define out(x) cout<<#x<<":"<<(x)<<endl
39 #define tst(a) cout<<#a<<endl
40 #define CINBEQUICKER std::ios::sync_with_stdio(false)
41 
42 typedef vector<int> VI;
43 typedef vector<string> VS;
44 typedef vector<double> VD;
45 typedef long long int64;
46 
47 const double eps = 1e-8;
48 const double PI = atan(1.0)*4;
49 const int inf = 2139062143 / 2;
50 
51 inline int MyMod( int a , int b ) { return (a%b+b)%b;}
52 
53 class StreetWalking
54 {
55     public:
56         long long minTime(int x, int y, int wt, int st){
57             if (st >= wt*2) return ((int64)x + y) * wt;
58 
59             if (x < y) swap(x, y);
60             int64 t = (int64)y * st;
61             int64 dif = x - y;
62             if (st < wt){
63                 if (dif & 1) return t + (dif-1) * st + wt;
64                 return t + dif * st;
65             }
66             return t + dif * wt;
67         }
68         
69 // BEGIN CUT HERE
70     public:
71     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(); if ((Case == -1) || (Case == 6)) test_case_6(); }
72     private:
73     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(); }
74     void verify_case(int Case, const long long &Expected, const long long &Received) { cerr << "Test Case #" << Case << "..."; if (Expected == Received) cerr << "PASSED" << endl; else { cerr << "FAILED" << endl; cerr << "	Expected: "" << Expected << '"' << endl; cerr << "	Received: "" << Received << '"' << endl; } }
75     void test_case_0() { int Arg0 = 4; int Arg1 = 2; int Arg2 = 3; int Arg3 = 10; long long Arg4 = 18LL; verify_case(0, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
76     void test_case_1() { int Arg0 = 4; int Arg1 = 2; int Arg2 = 3; int Arg3 = 5; long long Arg4 = 16LL; verify_case(1, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
77     void test_case_2() { int Arg0 = 2; int Arg1 = 0; int Arg2 = 12; int Arg3 = 10; long long Arg4 = 20LL; verify_case(2, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
78     void test_case_3() { int Arg0 = 25; int Arg1 = 18; int Arg2 = 7; int Arg3 = 11; long long Arg4 = 247LL; verify_case(3, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
79     void test_case_4() { int Arg0 = 24; int Arg1 = 16; int Arg2 = 12; int Arg3 = 10; long long Arg4 = 240LL; verify_case(4, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
80     void test_case_5() { int Arg0 = 10000000; int Arg1 = 50000000; int Arg2 = 800; int Arg3 = 901; long long Arg4 = 41010000000LL; verify_case(5, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
81     void test_case_6() { int Arg0 = 135; int Arg1 = 122; int Arg2 = 43; int Arg3 = 29; long long Arg4 = 3929LL; verify_case(6, Arg4, minTime(Arg0, Arg1, Arg2, Arg3)); }
82 
83 // END CUT HERE
84 
85 };
86 //by plum rain
87 // BEGIN CUT HERE
88 int main()
89 {
90     //freopen( "a.out" , "w" , stdout );    
91     StreetWalking ___test;
92     ___test.run_test(-1);
93        return 0;
94 }
95 // END CUT HERE

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