单链表是否相交

  1 # include<stdio.h>

  2 struct Slist{

  3     int size;

  4     struct sl* head;

  5 };

  6 struct sl{

  7     int k;

  8     struct sl* next;

  9 };

 10 typedef struct Slist Sl;

 11 typedef struct sl sl;

 12 void init(Sl* m,int k){

 13     sl* p = (sl *)malloc(sizeof(sl));    

 14     p->k = k;

 15     p->next = NULL;

 16     m->head =p;

 17     m->size = 1;

 18 }

 19 

 20 sl* add(Sl* m,int key ){

 21     sl* p=(sl *)malloc(sizeof(sl)); 

 22     sl* q = (sl *)malloc(sizeof(sl));

 23     p->k = key;

 24     p->next = NULL;

 25     q = m->head;

 26     while (q->next != NULL)

 27         q = q->next;

 28     q->next = p;

 29     m->size++;

 30     return p;

 31 }

 32 

 33 void FanZhuan(Sl* m){                            //链表反转

 34 

 35     sl* p = m->head;

 36     sl* q =NULL; 

 37     sl* r =NULL;

 38     while (p->next!=NULL){

 39 

 40         q = p->next;

 41         p->next = r;

 42         r = p;

 43         p = q;

 44     }

 45     q->next = r;

 46     m->head = q;

 47 }

 48 

 49 void BianLi(Sl* m){                                 //遍历链表

 50 

 51     sl* a = m->head;

 52     printf(" \n");

 53     while (a != NULL){

 54         printf("%d",a->k);

 55         a = a->next;

 56     }

 57 }

 58 

 59 sl* CheckLoop(Sl* m){                                //测试是否有环

 60     sl* a = m->head;

 61     sl* b = m->head;

 62     while (b!=NULL){

 63         a = a->next;

 64         if (b->next == NULL)

 65             return NULL;

 66         if (b->next->next == NULL)

 67             return NULL;

 68         b = b->next->next;

 69         if (a == b)

 70             return a;

 71     }

 72     return NULL;

 73 }

 74 

 75 int NloopCheck(Sl* f,Sl* n){            //两者均无环，测相交

 76     sl* k1 = f->head;

 77     sl* k2 = n->head;

 78     while (k1->next!=NULL)

 79     {

 80         k1 = k1->next;

 81     }                                   //取得表k1的最后一个节点

 82     while (k2 != NULL){

 83         k2 = k2->next;

 84         if (k2 == k1)

 85         {

 86              return 1;

 87         }

 88     }

 89     return 0;

 90 }

 91 

 92 void Check(Sl*t1,Sl*t2){                     //测试是否相交

 93 

 94     sl* Y1 = CheckLoop(t1);                  //先测两个表的每个表是否有环

 95     sl* Y2 = CheckLoop(t2);

 96 //    if (Y1 != NULL)

 97 //        printf("The first have loop!\n");

 98 //    if (Y2 != NULL)

 99 //        printf("The second have loop!");                        

100 

101     int y1 = (Y1 != NULL);

102     int y2 = (Y2 != NULL);

103     int y = y1 + y2;

104     int yes = 0;

105     sl* test = NULL;

106     switch (y)

107     {

108     case 0:                                       //均无环

109         printf("\n Two have no loop!");

110         yes = NloopCheck(t1, t2);

111         break;

112 

113     case 1:                                       //一个有环，一个没有

114         printf("\n One Have loop!");

115         yes = 0;

116         break;

117 

118     case 2:                                       //两者都有环

119         printf("\n Two have loop!");

120         test = t2->head;

121         while (1)

122         {

123             if (test == Y2)

124             {

125                 yes = 1;

126                 break;

127             }

128             test = test->next;

129         }

130         break;

131     default:

132         break;

133     }

134 

135     if (yes == 1)

136         printf("\n Have intersection!");

137     else

138         printf("\n Don't have intersection!");

139 }

140 

141 void main(){

142     Sl* t1 = (Sl*)malloc(sizeof(Sl));                 //创建带环链表t1

143     t1->size=0;

144     t1->head = NULL;

145     init(t1,8);

146     add(t1, 3);

147     add(t1, 2);

148     sl* t1Start=add(t1, 1);                           //loop start!

149     add(t1, 0);

150     add(t1, 9);

151     sl* t2Start=add(t1, 10);

152     t2Start->next = t1Start;                           //Add loop!

153     

154     Sl* t2 = (Sl*)malloc(sizeof(Sl));                 //创建链表t2与t1相交

155     t2->size = 0;

156     t2->head = NULL;

157     init(t2, 8);

158     add(t2, 3);

159     add(t2, 2);

160     sl* w2 = add(t2, 1);

161     w2->next = t2Start;

162 

163 

164     Sl* t3 = (Sl*)malloc(sizeof(Sl));                 //创建五环链表t3

165     t3->size = 0;

166     t3->head = NULL;

167     init(t3, 8);

168     add(t3, 3);

169     add(t3, 2);

170     sl* w3= add(t3, 1);

171     add(t3,7);

172     add(t3,27);

173 

174     Sl* t4 = (Sl*)malloc(sizeof(Sl));                 //创建链表t4与t3相交

175     t4->size = 0;

176     t4->head = NULL;

177     init(t4, 8);

178     add(t4, 3);

179     add(t4, 2);

180     sl* w4 = add(t4, 1);

181     w4->next = w3;

182 

183     Sl* t5 = (Sl*)malloc(sizeof(Sl));                  //创建链表t5，不与上相交

184     t5->size = 0;

185     t5->head = NULL;

186     init(t5, 8);

187     add(t5, 53);

188     add(t5, 42);

189 printf("\n SingList t1 and t2:");

190 Check(t1, t2);

191 printf("\n\n SingList t3 and t4:");

192 Check(t3, t4);

193 printf("\n\n SingList t1 and t3:");

194 Check(t3, t1);

195 printf("\n\n SingList t3and t5:");

196 Check(t5, t3);

197     

198     

199     

200     

201     system("pause");

202 }

 

执行效果图如下：