UVa978 - Lemmings Battle!(优先级队列)

题意：给出两个队及每个队员的战斗力，b个战场，每一轮从两个队中选中b个职员来打斗，赢的队员进入下一轮，直到其中的一个队赢或者打平。

思路：将两个队放入两个优先级队列中，每次从两个队列中取出b个元素，放入到两上数组中，将两个数组进行比较，将不为0的数组元素重新加入队列中。

代码如下：

#include <iostream>
#include <queue>
#include <vector>
#include <fstream>

class Solution
{
public:
void init(int b, int sg, int sb)
{
m_b = b; m_sg = sg; m_sb = sb;

while (!g_queue.empty()) g_queue.pop();
while (!b_queue.empty()) b_queue.pop();
}

void add_g(int num)
{
g_queue.push(num);
}

void add_b(int num)
{
b_queue.push(num);
}

void solve()
{
std::vector<int> vg(m_b), vb(m_b);
while (!g_queue.empty() && !b_queue.empty())
{
for (int i = 0; i < m_b; i++)
{
if (g_queue.empty()) break;
int num = g_queue.top(); g_queue.pop();
vg[i] = num;
}

for (int i = 0; i < m_b; i++)
{
if (b_queue.empty()) break;
int num = b_queue.top(); b_queue.pop();
vb[i] = num;
}

for (int i = 0; i < m_b; i++)
{
if (vg[i] > vb[i])
{
vg[i] -= vb[i];
vb[i] = 0;
}
else if (vg[i] < vb[i])
{
vb[i] -= vg[i];
vg[i] = 0;
}
else
{
vg[i] = vb[i] = 0;
}
}

for (int i = 0; i < m_b; i++)
{
if (vg[i] != 0)
{
g_queue.push(vg[i]);
vg[i] = 0;
}

if (vb[i] != 0)
{
b_queue.push(vb[i]);
vb[i] = 0;
}
}
}

if (g_queue.empty() && b_queue.empty())
{
std::cout << "green and blue died" << std::endl;
}
else if (g_queue.empty())
{
std::cout << "blue wins" << std::endl;
while (!b_queue.empty())
{
int num = b_queue.top(); b_queue.pop();
std::cout << num << std::endl;
}
}
else
{
std::cout << "green wins" << std::endl;
while (!g_queue.empty())
{
int num = g_queue.top(); g_queue.pop();
std::cout << num << std::endl;
}
}

}

private:
int m_b, m_sg, m_sb;
std::priority_queue<int> g_queue, b_queue;
};

int main() {
#ifndef ONLINE_JUDGE
std::ifstream fin("e:\\program\\clion\\uva_in.txt");
std::streambuf* old = std::cin.rdbuf(fin.rdbuf());
#endif

int n;
std::cin >> n;
Solution solver;
while (n--)
{
int b, sg, sb;
std::cin >> b >> sg >> sb;
solver.init(b, sg, sb);
for (int i = 0; i < sg; i++)
{
int num;
std::cin >> num;
solver.add_g(num);
}

for (int i = 0; i < sb; i++)
{
int num;
std::cin >> num;
solver.add_b(num);
}

solver.solve();
if (n) std::cout << std::endl;
}

#ifndef ONLINE_JUDGE
std::cin.rdbuf(old);
#endif
return 0;
}