图的最短路径

来源：互联网发布：三明学院网络教学平台编辑：程序博客网时间：2024/05/16 07:21
#include <iostream>using namespace std;const int MAXVERTEXNUM = 100;const int MAX_WEIGHT = 32767;struct MGraph{    char vers[MAXVERTEXNUM];    int  edges[MAXVERTEXNUM][MAXVERTEXNUM];    int  n, e;};void CreateMGraph(MGraph *G, int adjmatrix[][MAXVERTEXNUM]){    cout << "请输入图的顶点和边数:" << endl;    cin >> G->n >> G->e;    cout << "请输入顶点信息:" << endl;    for(int i = 0; i < G->n; i++)        cin >> G->vers[i];    for(i = 0; i < G->n; i++)        for(int j = 0; j < G->n; j++)            adjmatrix[i][j] = MAX_WEIGHT;    for(int k = 0; k < G->e; k++)    {        int x, y, dut;        cout << "请输入第" << k + 1 << "条边所依附的顶点及其权值:" << endl;        cin >> x >> y >> dut;        adjmatrix[x][y] = dut;    }}void ShortestPath(MGraph *G, int adjmatrix[][MAXVERTEXNUM], int v){    int n = G->n;    int i, j;    int dist[MAXVERTEXNUM];    int path[MAXVERTEXNUM];    int s[MAXVERTEXNUM];    for(i = 0; i < n; i++)    {        s[i] = 0;        dist[i] = adjmatrix[v][i];        if(i != v && dist[i] < 32767)            path[i] = v;        else            path[i] = -1;    }    s[v] = 1;    i = (v + 1) % n;    while(i != v)    {        int mindist = MAX_WEIGHT;        int u = 0;        for(j = 0; j < n; j++)            if(s[j] == 0 && dist[j] < mindist)            {                u = j;                mindist = dist[j];            }        if(mindist == MAX_WEIGHT)            break;        s[u] = 1;        for(j = 0; j < n; j++)            if(s[j] == 0 && adjmatrix[u][j] < MAX_WEIGHT && adjmatrix[u][j] + dist[u] < dist[j])            {                dist[j] = dist[u] + adjmatrix[u][j];                path[j] = u;            }        i = (i + 1) % n;    }    cout << "从顶点" << G->vers[v] << "到其它顶点的最短路径如下:" << endl;    i = (v + 1) % n;    while(i != v)    {        j = i;        if(path[j] == -1)        {            cout << "没有" << G->vers[v] << "到" << G->vers[j] << "的路径!" << endl;        }        if(dist[i] < MAX_WEIGHT)        {            char pathnum[MAXVERTEXNUM];            int k = 0;            while(path[j] != -1)            {                pathnum[k] = j;                k++;                j = path[j];            }            cout << G->vers[v] << " ";            while(k > 0)                cout << "->" << G->vers[pathnum[--k]] << " ";            cout << "长度为:" << dist[i] << endl;        }        i = (i + 1) % n;    }}int main(){    int adjmatrix[MAXVERTEXNUM][MAXVERTEXNUM];    MGraph G;    CreateMGraph(&G, adjmatrix);    ShortestPath(&G, adjmatrix, 0);    return 0;}
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