rocj
2/4/2018 - 4:07 AM

[字符串轮转（改进）] 对给定的字符串进行轮转，时间复杂度为 O(n) #字符串处理

[字符串轮转（改进）] 对给定的字符串进行轮转，时间复杂度为 O(n) #字符串处理

string-rotate.cpp
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#include <iostream>
#include <cstring>

using namespace std;

void ReverseString(char* s, int from, int to) {
    while(from < to) {
        char t = s[from];
        s[from++] = s[to];
        s[to--] = t;
    }
}

void LeftRotateString(char* s, int m) {
    int n = strlen(s);
    m %= n; //左移 m 位与左移 m%n 等价
    ReverseString(s, 0, m - 1); //反转 [0, m-1]
    ReverseString(s, m, n - 1); //反转 [m, n-1]
    ReverseString(s, 0, n - 1); //整体反转
}

int main() {
    char s[] = {"hello"};
    cout << s << endl;
    LeftRotateString(s, 2);
    cout << s << endl;
    return 0;
}