Bellman-Ford——C++实现版

// Bellman_Ford.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <iostream>
#include <stack>
#define MAX_VALUE 1000
using namespace std;

struct Edge{
	int Begin;
	int End;
	int Weight;
	int Pre;
};
struct MGraph
{
	Edge edges[MAX_VALUE];
	int iVertexCount, iEdageCount;
};
void ReadDate(MGraph *mGraph, int *iBegin, int *iEnd);
bool Bellman_Ford(MGraph *mGraph, int *pArrDis, int *pArrPath, int iBegin);
void PrintResult(int *pArrDis, int *pArrPath, int iBegin, int iEnd);

int main()
{
	int iBegin, iEnd;
	int *pArrPath = new int[MAX_VALUE];
	int *pArrDis = new int[MAX_VALUE];
	MGraph mGraph;
	ReadDate(&mGraph, &iBegin, &iEnd);
	Bellman_Ford(&mGraph, pArrDis, pArrPath, iBegin);
	PrintResult(pArrDis, pArrPath, iBegin, iEnd);
	system("pause");
	return 0;
}

void ReadDate(MGraph *mGraph, int *iBegin, int *iEnd){
	//cout << "请输入顶点数量" << endl;
	//cin >> mGraph->iVertexCount;
	//cout << "请输入邻接矩阵数据:" << endl;
	//for (int iRow = 1; iRow <= mGraph->iVertexCount; iRow++){
	//	for (int iCol = 1; iCol <= mGraph->iVertexCount; iCol++){
	//		cin >> mGraph->edges[iRow][iCol];
	//	}
	//}

	cout << "请输入顶点数和边数" << endl;
	cin >> mGraph->iVertexCount >> mGraph->iEdageCount;

	cout << "请输入连通边及权重" << endl;
	for (int i = 1; i <= mGraph->iEdageCount; i++){
		cin >> mGraph->edges[i].Begin >> mGraph->edges[i].End >> mGraph->edges[i].Weight;
	}

	cout << "请输入查询的起点和终点" << endl;
	cin >> *iBegin >> *iEnd;
}

bool Bellman_Ford(MGraph *mGraph, int *pArrDis, int *pArrPath, int iBegin){

	for (int i = 0; i <= mGraph->iVertexCount; i++){
		pArrDis[i] = MAX_VALUE;
	}
	for (int i = 0; i <= mGraph->iVertexCount; i++){
		pArrPath[i] = -1;
	}
	pArrDis[iBegin] = 0;
	for (int i = 1; i <= mGraph->iVertexCount; i++){
		bool flag = true;
		for (int j = 1; j <= mGraph->iEdageCount; j++){
			if (pArrDis[mGraph->edges[j].End] > pArrDis[mGraph->edges[j].Begin] + mGraph->edges[j].Weight){
				pArrDis[mGraph->edges[j].End] = pArrDis[mGraph->edges[j].Begin] + mGraph->edges[j].Weight;
				pArrPath[mGraph->edges[j].End] = mGraph->edges[j].Begin;
				flag = false;
			}
		}
		if (flag){
			break;
		}
		if (i == mGraph->iVertexCount){
			return false;
		}
	}
	return true;
}

void PrintResult(int *pArrDis, int *pArrPath, int iBegin, int iEnd){

	cout << "从" << iBegin << "开始到" << iEnd << "的最短路径长度为";
	cout << pArrDis[iEnd] << endl;
	cout << "所经过的最短路径节点为:";

	stack<int> stackVertices;
	int k = iEnd;
	do{
		stackVertices.push(k);
		k = pArrPath[k];
	} while (k != pArrPath[k] && k != -1);
	cout << stackVertices.top();
	stackVertices.pop();

	unsigned int nLength = stackVertices.size();
	for (unsigned int nIndex = 0; nIndex < nLength; nIndex++)
	{
		cout << " -> " << stackVertices.top();
		stackVertices.pop();
	}
	cout << endl;
}

《Bellman-Ford——C++实现版》
《Bellman-Ford——C++实现版》

    原文作者:Bellman - ford算法
    原文地址: https://blog.csdn.net/u012102306/article/details/49905391
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