<pre name="code" class="cpp">#include<iostream>
#include<vector>
#include<fstream>
using namespace std;

typedef struct{

	//进程号
	int numberOfThread;
	//该进程对每个资源的需求量
	int countOf_A, countOf_B;
	int countOf_C;
	//该进程是否完成
	bool isFinish;

}infor;

//在银行家算法中，总共需要4个向量
//每个资源拥有的剩余资源数量
vector<int>avliable;
//每个资源已经分配的，最大需求，和需要的
vector<infor>allocation;
vector<infor>max;
vector<infor>need;

void getInforOfThread();
void getNeed();
void getReslut();

int main(int argc, char argv[])
{
	getInforOfThread();
	getNeed();
	cout << "获取分配资源后剩余资源数：" << endl;
	for (int i = 0; i < 3; i++)
	{
		int num;
		cin >> num;
		avliable.push_back(num);
	}
	getReslut();
	return 0;
}

void getReslut()
{
	int countNum[3];
	auto iterOfAvliable = avliable.begin();
	int i = 0;
	for (; iterOfAvliable != avliable.end(); iterOfAvliable++)
	{
		countNum[i++] = *iterOfAvliable;
	}
	int j = 0;
	int count = 0;
	bool flag = false;
	int length = need.size();
	while (j < length)
	{
		if (count < length)
		{
			auto iterOfNeed = need.begin();
			auto iterOfMax = max.begin();
			for (; iterOfNeed != need.end(); iterOfNeed++)
			{
				if (countNum[0] >= iterOfNeed->countOf_A&&countNum[1] >= iterOfNeed->countOf_B&&countNum[2] >= iterOfNeed->countOf_C&&iterOfNeed->isFinish == false)
				{
					//当前拥有资源数量满足该进程所需要的数量 
					//打印出当前每个资源的剩余个数
					for (int i = 0; i < 3; i++)
					{
						cout << i << "类资源: " << countNum[i] << "   ";
					}
					cout << endl;
					//打印出当前可以被执行的进程所需要的资源数
					cout << "当前可执行进程号：" << iterOfNeed->numberOfThread << "  A:" << iterOfNeed->countOf_A << "  B:" << iterOfNeed->countOf_B << "  C:" << iterOfNeed->countOf_C << endl;
					iterOfNeed->isFinish = true;
					cout << "进程p" << iterOfNeed->numberOfThread << endl;
					for (; iterOfMax != max.end(); iterOfMax++)
					{
						if (iterOfMax->numberOfThread == iterOfNeed->numberOfThread&&iterOfMax->isFinish == false)
							break;
					}
					countNum[0] += iterOfMax->countOf_A;
					countNum[1] += iterOfMax->countOf_B;
					countNum[2] += iterOfMax->countOf_C;
					iterOfMax->isFinish = true;
					count++;
					break;
				}
			}
		}
		else
		{
			flag = true;
			break;
		}
		j++;
	}
	if (flag)
	{
		cout << "系统不安全" << endl;
		exit(true);
	}
}

void getInforOfThread()
{
	//获得每个进程所需的资源最大量，和每个进程已经分配的数量
	ifstream cin("test.txt");
	int numberOfThread, count_A, count_B, count_C;
	int alloc_A, alloc_B, alloc_C;
	infor str, ptr;
	while (!cin.eof())
	{
		cin >> numberOfThread >> count_A >> count_B >> count_C >> alloc_A >> alloc_B >> alloc_C;
		str.numberOfThread = numberOfThread;
		str.countOf_A = count_A;
		str.countOf_B = count_B;
		str.countOf_C = count_C;
		str.isFinish = false;
		max.push_back(str);
		ptr.numberOfThread = numberOfThread;
		ptr.countOf_A = alloc_A;
		ptr.countOf_B = alloc_B;
		ptr.countOf_C = alloc_C;
		ptr.isFinish = false;
		allocation.push_back(ptr);
	}
	cin.close();
}

void getNeed()
{
	//计算每个进程剩余所需资源的数量
	auto iterOfAllocation = allocation.begin();
	auto iterOfMax = max.begin();
	infor temp;
	for (; iterOfAllocation != allocation.end(), iterOfMax != max.end(); iterOfAllocation++, iterOfMax++)
	{
		temp.numberOfThread = iterOfAllocation->numberOfThread;
		temp.countOf_A = iterOfMax->countOf_A - iterOfAllocation->countOf_A;
		temp.countOf_B = iterOfMax->countOf_B - iterOfAllocation->countOf_B;
		temp.countOf_C = iterOfMax->countOf_C - iterOfAllocation->countOf_C;
		temp.isFinish = false;
		//temp.countOf_D = iterOfMax->countOf_D - iterOfAllocation->countOf_D;
		need.push_back(temp);
	}
}

<img src="https://img-blog.csdn.net/20160627164659075?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

<img src="https://img-blog.csdn.net/20160627164743716?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />