数据结构学习第二十天

15:44:43 2019-09-04

勉強します

 

PTA第20题 Dijkstra算法的变形  其实是加了一个变量来辅助判别 那如果影响的判断的变量增加 就需要多加变量来 继续进行判断

  1 #define _CRT_SECURE_NO_WARNINGS  
  2 #include<stdio.h>
  3 #include<malloc.h>
  4 #define INIFITY 65635
  5 int Departure;
  6 int Destination;
  7 typedef struct TypeInt Element;
  8 struct  TypeInt
  9 {
 10     int Length;
 11     int Price;
 12 };
 13 typedef struct ENode* Edge;
 14 struct ENode
 15 {
 16     int V1, V2;
 17     int Length;
 18     int Price;
 19 };
 20 
 21 typedef struct Graph* MGraph;
 22 struct Graph
 23 {
 24     int Nv;
 25     int Ne;
 26     Element G[500][500];
 27 };
 28 
 29 MGraph CreateGraph(int MaxVertex)
 30 {
 31     MGraph Graph = (MGraph)malloc(sizeof(struct Graph));
 32     Graph->Nv = MaxVertex;
 33     Graph->Ne = 0;
 34     for (int i = 0; i < Graph->Nv; i++)
 35         for (int j = 0; j < Graph->Nv; j++)
 36         {
 37                 Graph->G[i][j].Length= INIFITY;
 38                 Graph->G[i][j].Price = INIFITY;
 39         }
 40     return Graph;
 41 }
 42 
 43 void Insert(MGraph Graph, Edge E)
 44 {
 45     Graph->G[E->V1][E->V2].Length= E->Length;
 46     Graph->G[E->V2][E->V1].Length= E->Length;
 47     Graph->G[E->V1][E->V2].Price = E->Price;
 48     Graph->G[E->V2][E->V1].Price = E->Price;
 49 }
 50 
 51 MGraph BuildGraph()
 52 {
 53     MGraph Graph;
 54     Edge E;
 55     int Nv;
 56     scanf("%d", &Nv);
 57     Graph = CreateGraph(Nv);
 58     scanf("%d %d %d", &Graph->Ne,&Departure,&Destination);
 59     for (int i = 0; i < Graph->Ne; i++)
 60     {
 61         E = (Edge)malloc(sizeof(struct ENode));
 62         scanf("%d %d %d %d\n", &(E->V1), &(E->V2), &(E->Length),&(E->Price));
 63         Insert(Graph, E);
 64     }
 65     return Graph;
 66 }
 67 
 68 int IsEdge(MGraph Graph, int V, int W)
 69 {
 70     return (Graph->G[V][W].Length < INIFITY) ? 1 : 0;
 71 }
 72 int Dist[500];        //从源点到某点的路径长度
 73 int Price[500];        //从源点到某点的价格
 74 int Path[500];        //记录路径
 75 int Collected[500]; //记录是否收录
 76 int FindMinDist(MGraph Graph)
 77 {
 78     int MinDist = INIFITY;
 79     int V;
 80     for (int i = 0; i < Graph->Nv; i++)
 81     {
 82         if (!Collected[i]&&Dist[i] < MinDist)
 83         {
 84             MinDist = Dist[i];
 85             V = i;
 86         }
 87     }
 88     if (MinDist < INIFITY)
 89         return V;
 90     else
 91         return 0;
 92 }
 93 void Dijkstra(MGraph Graph,int S)
 94 {
 95     //先初始化源点连接的点
 96     for (int i = 0; i < Graph->Nv; i++)
 97     {
 98         Dist[i] = Graph->G[S][i].Length;
 99         Price[i] = Graph->G[S][i].Price;
100         if (IsEdge(Graph,S,i))
101             Path[i] = S;
102         else
103             Path[i] = -1;
104     }
105 
106     Collected[S] = 1;
107     Dist[S] = 0;
108     Price[S] = 0;
109 
110     while (1)
111     {
112         int V = FindMinDist(Graph);
113         if (!V)
114             break;
115         Collected[V] = 1;
116         for (int i = 0; i < Graph->Nv; i++)
117         {
118             if (!Collected[i] && IsEdge(Graph, V, i))
119             {
120                 if (Dist[V] + Graph->G[V][i].Length < Dist[i])
121                 {
122                     Dist[i] = Dist[V] + Graph->G[V][i].Length;
123                     Path[i] = V;
124                     Price[i] = Price[V] + Graph->G[V][i].Price;
125                 }
126                 else if (Dist[V] + Graph->G[V][i].Length == Dist[i]) 
127                 {
128                     if (Price[V] + Graph->G[V][i].Price < Price[i])
129                     {
130                         Price[i] = Price[V] + Graph->G[V][i].Price;
131                         Path[i] = V;
132                     }
133                 }
134             }
135                 
136         }
137     }
138 }
139 int main()
140 {
141     MGraph Graph = BuildGraph();
142     Dijkstra(Graph,Departure);
143     printf("%d %d", Dist[Destination], Price[Destination]);
144     return 0;
145 }

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