Cracking the Coding Interview, 4 Edition - 150 Programming Interview Questions and Solutions

Recommendations

Info

Solutions to Chapter 16 | Low Level 16.5 Write a program to find whether a machine is big endian or little endian. SOLUTION pg 82 1 #define BIG_ENDIAN 0 2 #define LITTLE_ENDIAN 1 3 int TestByteOrder() { 4 short int word = 0x0001; 5 char *byte = (char *) &word; 6 return (byte[0] ? LITTLE_ENDIAN : BIG_ENDIAN); 7 } 2 4 1 Cracking the Coding Interview | Knowledge Based
Solutions to Chapter 16 | Low Level 16.6 Discuss how would you make sure that a process doesn’t access an unauthorized part of the stack. SOLUTION pg 82 As with any ambiguously worded interview question, it may help to probe the interviewer to understand what specifically you’re intended to solve. Are you trying to prevent code that has overflowed a buffer from compromising the execution by overwriting stack values? Are you trying to maintain some form of thread-specific isolation between threads? Is the code of interest native code like C++ or running under a virtual machine like Java? Remember that, in a multi-threaded environment, there can be multiple stacks in a process. NATIVE CODE One threat to the stack is malicious program input, which can overflow a buffer and overwrite stack pointers, thus circumventing the intended execution of the program. If the interviewer is looking for a simple method to reduce the risk of buffer overflows in native code, modern compilers provide this sort of stack protection through a command line option. With Microsoft’s CL, you just pass /GS to the compiler. With GCC, you can use -fstack-protector-all. For more complex schemes, you could set individual permissions on the range of memory pages representing the stack section you care about. In the Win32 API, you’d use the VirtualProtect API to mark the page PAGE_READONLY or PAGE_NOACCESS. This will cause the code accessing the region to go through an exception on access to the specific section of the stack. Alternately, you could use the HW Debug Registers (DRs) to set a read or write breakpoint on the specific memory addresses of interest. A separate process could be used to debug the process of interest, catch the HW exception that would be generated if this section of the stack were accessed. However, it’s very important to note that under normal circumstances, threads and processes are not means of access control. Nothing can prevent native code from writing anywhere within the address space of its process, including to the stack. Specifically, there is nothing to prevent malicious code in the process from calling VirtualProtect and marking the stack sections of interest PAGE_EXECUTE_READWRITE. Equally so, nothing prevents code from zeroing out the HW debug registers, eliminating your breakpoints. In summary, nothing can fully prevent native code from accessing memory addresses, including the stack, within its own process space. MANAGED CODE CareerCup.com 2 4 2
Page 1 and 2:
CRACKING THE FOURTH EDITION C O D I
Page 3 and 4:
Table of Contents Chapter 7 | Objec
Page 5 and 6:
Introduction Something’s Wrong We
Page 7 and 8:
Behind the Scenes For many candidat
Page 9 and 10:
Behind the Scenes | The Amazon Inte
Page 11 and 12:
Behind the Scenes | The Apple Inter
Page 13 and 14:
Interview War Stories The View from
Page 15 and 16:
Interview War Stories | Pop Divas P
Page 17 and 18:
Interview War Stories | You Can (Ma
Page 19 and 20:
Interview War Stories | Spider Sens
Page 21 and 22:
Before the Interview | Resume Advic
Page 23 and 24:
Before the Interview | Behavioral P
Page 25 and 26:
Before the Interview | Technical Pr
Page 27 and 28:
The Interview and Beyond
Page 29 and 30:
At the Interview | Handling Behavio
Page 31 and 32:
At the Interview | Handling Technic
Page 33 and 34:
At the Interview | Five Algorithm A
Page 35 and 36:
At the Interview | Five Algorithm A
Page 37 and 38:
At the Interview | The Offer and Be
Page 39 and 40:
At the Interview | Top Ten Mistakes
Page 41 and 42:
At the Interview | Frequently Asked
Page 43 and 44:
Interview Questions
Page 45 and 46:
Chapter 1 | Arrays and Strings Hash
Page 47 and 48:
Chapter 2 | Linked Lists How to App
Page 49 and 50:
Chapter 3 | Stacks and Queues How t
Page 51 and 52:
Chapter 4 | Trees and Graphs How to
Page 53 and 54:
Part 2 Concepts and Algorithms
Page 55 and 56:
Chapter 5 | Bit Manipulation 5.1 Yo
Page 57 and 58:
Chapter 6 | Brain Teasers 6.1 Add a
Page 59 and 60:
Chapter 7 | Object Oriented Design
Page 61 and 62:
Chapter 8 | Recursion 8.1 Write a m
Page 63 and 64:
Chapter 9 | Sorting and Searching 9
Page 65 and 66:
Chapter 10 | Mathematical 10.1 You
Page 67 and 68:
Chapter 11 | Testing 11.1 Find the
Page 69 and 70:
Chapter 12 | System Design and Memo
Page 71 and 72:
Chapter 13 | C++ How To Approach: A
Page 73 and 74:
Chapter 14 | Java How to Approach:
Page 75 and 76:
Chapter 15 | Databases How to Appro
Page 77 and 78:
Chapter 16 | Low Level How to Appro
Page 79 and 80:
Chapter 17 | Networking How to Appr
Page 81 and 82:
Chapter 18 | Threads and Locks How
Page 83 and 84:
Part 4 Additional Review Problems
Page 85 and 86:
Chapter 19 | Moderate _____________
Page 87 and 88:
Chapter 20 | Hard Input: DAMP, LIKE
Page 89 and 90:
Solutions
Page 91 and 92:
Solutions to Chapter 1 | Arrays and
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Solutions to Chapter 2 | Linked Lis
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Solutions to Chapter 3 | Stacks and
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Solutions to Chapter 4 | Trees and
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Page 125 and 126:
Page 127 and 128:
Solutions to Chapter 5 | Bit Manipu
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Solutions to Chapter 6 | Brain Teas
Page 139 and 140:
Page 141 and 142:
Page 143 and 144:
Solutions to Chapter 7 | Object Ori
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
Solutions to Chapter 8 | Recursion
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Page 171 and 172:
Solutions to Chapter 9 | Sorting an
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Page 179 and 180:
Solutions to Chapter 10 | Mathemati
Page 181 and 182: Solutions to Chapter 10 | Mathemati
Page 189 and 190: Solutions to Chapter 11 | System De
Page 201 and 202: Solutions to Chapter 12 | Testing 1
Page 207 and 208: Solutions to Chapter 13 | C++ 13.2
Page 213 and 214: Solutions to Chapter 13 | C++ Then
Page 217 and 218: Solutions to Chapter 14 | Java 14.2
Page 223 and 224: Solutions to Chapter 15 | Databases
Page 229 and 230: Solutions to Chapter 16 | Low Level
Page 231: Solutions to Chapter 16 | Low Level
Page 241 and 242: Solutions to Chapter 17 | Networkin
Page 249 and 250: Solutions to Chapter 18 | Threads a
Page 257 and 258: Solutions to Chapter 19 | Moderate
Page 271 and 272: Solutions to Chapter 20 | Hard 2. O
Page 273 and 274: Solutions to Chapter 20 | Hard 20.3
Page 275 and 276: Solutions to Chapter 20 | Hard 10 1
Page 283 and 284:
Solutions to Chapter 20 | Hard 28 i
Page 285 and 286:
Solutions to Chapter 20 | Hard 23 }
Page 287 and 288:
Solutions to Chapter 20 | Hard Val_
Page 289 and 290:
Solutions to Chapter 20 | Hard 20.1
Page 291 and 292:
Index A arithmetic 108, 131, 143, 1
Page 293:
Mock Interviews Mock Interviews Stu
show all

Cracking the Coding Interview, 4 Edition - 150 Programming Interview Questions and Solutions

Create successful ePaper yourself

Delete template?

Save as template?