/
016_LoopsInLists.cpp
189 lines (155 loc) · 3.9 KB
/
016_LoopsInLists.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
// Coding Interviews: Questions, Analysis & Solutions
// Harry He
#include <stdio.h>
#include "../Utility/list.h"
bool HasLoop(ListNode* pHead)
{
if(pHead == NULL)
return false;
ListNode* pSlow = pHead->m_pNext;
if(pSlow == NULL)
return false;
ListNode* pFast = pSlow->m_pNext;
while(pFast != NULL && pSlow != NULL)
{
if(pFast == pSlow)
return true;
pSlow = pSlow->m_pNext;
pFast = pFast->m_pNext;
if(pFast != NULL)
pFast = pFast->m_pNext;
}
return false;
}
// ==================== Test Code ====================
void Test(char* testName, ListNode* pHead, bool expected)
{
if(testName != NULL)
printf("%s begins: ", testName);
if(HasLoop(pHead) == expected)
printf("HasLoop Passed.\n");
else
printf("HasLoop FAILED.\n");
}
// A list has a node, without a loop
void Test1()
{
ListNode* pNode1 = CreateListNode(1);
Test("Test1", pNode1, false);
DestroyList(pNode1);
}
// A list has a node, with a loop
void Test2()
{
ListNode* pNode1 = CreateListNode(1);
ConnectListNodes(pNode1, pNode1);
Test("Test2", pNode1, true);
delete pNode1;
pNode1 = NULL;
}
// A list has multiple nodes, with a loop
void Test3()
{
ListNode* pNode1 = CreateListNode(1);
ListNode* pNode2 = CreateListNode(2);
ListNode* pNode3 = CreateListNode(3);
ListNode* pNode4 = CreateListNode(4);
ListNode* pNode5 = CreateListNode(5);
ConnectListNodes(pNode1, pNode2);
ConnectListNodes(pNode2, pNode3);
ConnectListNodes(pNode3, pNode4);
ConnectListNodes(pNode4, pNode5);
ConnectListNodes(pNode5, pNode3);
Test("Test3", pNode1, true);
delete pNode1;
pNode1 = NULL;
delete pNode2;
pNode2 = NULL;
delete pNode3;
pNode3 = NULL;
delete pNode4;
pNode4 = NULL;
delete pNode5;
pNode5 = NULL;
}
// A list has multiple nodes, with a loop
void Test4()
{
ListNode* pNode1 = CreateListNode(1);
ListNode* pNode2 = CreateListNode(2);
ListNode* pNode3 = CreateListNode(3);
ListNode* pNode4 = CreateListNode(4);
ListNode* pNode5 = CreateListNode(5);
ConnectListNodes(pNode1, pNode2);
ConnectListNodes(pNode2, pNode3);
ConnectListNodes(pNode3, pNode4);
ConnectListNodes(pNode4, pNode5);
ConnectListNodes(pNode5, pNode1);
Test("Test4", pNode1, true);
delete pNode1;
pNode1 = NULL;
delete pNode2;
pNode2 = NULL;
delete pNode3;
pNode3 = NULL;
delete pNode4;
pNode4 = NULL;
delete pNode5;
pNode5 = NULL;
}
// A list has multiple nodes, with a loop
void Test5()
{
ListNode* pNode1 = CreateListNode(1);
ListNode* pNode2 = CreateListNode(2);
ListNode* pNode3 = CreateListNode(3);
ListNode* pNode4 = CreateListNode(4);
ListNode* pNode5 = CreateListNode(5);
ConnectListNodes(pNode1, pNode2);
ConnectListNodes(pNode2, pNode3);
ConnectListNodes(pNode3, pNode4);
ConnectListNodes(pNode4, pNode5);
ConnectListNodes(pNode5, pNode5);
Test("Test5", pNode1, true);
delete pNode1;
pNode1 = NULL;
delete pNode2;
pNode2 = NULL;
delete pNode3;
pNode3 = NULL;
delete pNode4;
pNode4 = NULL;
delete pNode5;
pNode5 = NULL;
}
// A list has multiple nodes, without a loop
void Test6()
{
ListNode* pNode1 = CreateListNode(1);
ListNode* pNode2 = CreateListNode(2);
ListNode* pNode3 = CreateListNode(3);
ListNode* pNode4 = CreateListNode(4);
ListNode* pNode5 = CreateListNode(5);
ConnectListNodes(pNode1, pNode2);
ConnectListNodes(pNode2, pNode3);
ConnectListNodes(pNode3, pNode4);
ConnectListNodes(pNode4, pNode5);
Test("Test6", pNode1, false);
DestroyList(pNode1);
}
// Empty list
void Test7()
{
Test("Test7", NULL, false);
}
int main(int argc, char* argv[])
{
Test1();
Test2();
Test3();
Test4();
Test5();
Test6();
Test7();
return 0;
}