JZ-C-42-Plus

剑指offer第四十二题-拓展：左旋转字符串：左旋转操作是把字符串前面的若干个字符转移到字符串的尾部，如输入"abcdefg"和数字2，左旋转2位后为："cdefgab"

  1 //============================================================================
  2 // Name        : JZ-C-42-Plus.cpp
  3 // Author      : Laughing_Lz
  4 // Version     :
  5 // Copyright   : All Right Reserved
  6 // Description : 左旋转字符串：左旋转操作是把字符串前面的若干个字符转移到字符串的尾部，如输入"abcdefg"和数字2，左旋转2位后为："cdefgab"
  7 //============================================================================
  8
  9 #include <iostream>
 10 #include <stdio.h>
 11 #include "StringUtil.h"
 12 #include <string.h>
 13 using namespace std;
 14
 15 char* LeftRotateString(char* pStr, int n) {
 16     if (pStr != NULL) {
 17         int nLength = static_cast<int>(strlen(pStr));
 18         if (nLength > 0 && n > 0 && n < nLength) {
 19             char* pFirstStart = pStr;
 20             char* pFirstEnd = pStr + n - 1;
 21             char* pSecondStart = pStr + n;
 22             char* pSecondEnd = pStr + nLength - 1;
 23             // 翻转字符串的前面n个字符
 24             Reverse(pFirstStart, pFirstEnd);
 25             // 翻转字符串的后面部分
 26             Reverse(pSecondStart, pSecondEnd);
 27             // 翻转整个字符串
 28             Reverse(pFirstStart, pSecondEnd);
 29         }
 30     }
 31
 32     return pStr;
 33 }
 34
 35 // ====================测试代码====================
 36 void Test(char* testName, char* input, int num, char* expectedResult) {
 37     if (testName != NULL)
 38         printf("%s begins: ", testName);
 39
 40     char* result = LeftRotateString(input, num);
 41
 42     if ((input == NULL && expectedResult == NULL)
 43             || (input != NULL && strcmp(result, expectedResult) == 0))
 44         printf("Passed.\n\n");
 45     else
 46         printf("Failed.\n\n");
 47 }
 48
 49 // 功能测试
 50 void Test1() {
 51     char input[] = "abcdefg";
 52     char expected[] = "cdefgab";
 53
 54     Test("Test1", input, 2, expected);
 55 }
 56
 57 // 边界值测试
 58 void Test2() {
 59     char input[] = "abcdefg";
 60     char expected[] = "bcdefga";
 61
 62     Test("Test2", input, 1, expected);
 63 }
 64
 65 // 边界值测试
 66 void Test3() {
 67     char input[] = "abcdefg";
 68     char expected[] = "gabcdef";
 69
 70     Test("Test3", input, 6, expected);
 71 }
 72
 73 // 鲁棒性测试
 74 void Test4() {
 75     Test("Test4", NULL, 6, NULL);
 76 }
 77
 78 // 鲁棒性测试
 79 void Test5() {
 80     char input[] = "abcdefg";
 81     char expected[] = "abcdefg";
 82
 83     Test("Test5", input, 0, expected);
 84 }
 85
 86 // 鲁棒性测试
 87 void Test6() {
 88     char input[] = "abcdefg";
 89     char expected[] = "abcdefg";
 90
 91     Test("Test6", input, 7, expected);
 92 }
 93
 94 int main(int argc, char** argv) {
 95     Test1();
 96     Test2();
 97     Test3();
 98     Test4();
 99     Test5();
100     Test6();
101
102     return 0;
103 }