分割字符串可以用双指针

【1455】检查单词是否为句中其他单词的前缀

前面这个是我写的:

#include <iostream>               // 输入输出
#include <vector>             // 可变长度数组
#include <unordered_map>      // hashmap
#include <stack>              // 栈
#include <string>             // 字符串
#include <queue>                // 队列

using namespace std;

/// <summary>
/// 输出容器中的内容
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="t"></param>
template<typename T>
void print(T t) {

    for (typename T::const_iterator it = t.begin(); it != t.end() - 1; ++it) {
        cout << *it << ", ";
    }

    cout << *(t.end() - 1) << endl;
}

////////////////////////////////////////////////////////////////////////////////
/// 这里放 OJ 的类

class Solution {
public:
    int isPrefixOfWord(string sentence, string searchWord) {

        int i = 0;
        int num = 0;
        while (true) {
            // 找到第一个非空格的字符
            while (sentence[i] == ' ' && i < sentence.length()) i++;
            // 判断是否没有找到
            if (i >= sentence.length() - 1) return -1;

            num++;
            int flag = 1;
            for (int j = 0; j < searchWord.length(); j++) {

                if (i + j > sentence.length()) return -1;

                if (searchWord[j] != sentence[i+j]) {
                    while (sentence[i] != ' ' && i < sentence.length()) i++;
                    flag = 0;
                    break;
                }
            }

            if (flag == 1) return num;
        }
    }
};

////////////////////////////////////////////////////////////////////////////////

int main() {

    /*print<vector<int>>({ 1, 2, 3, 4 });*/

    Solution s;

    cout << s.isPrefixOfWord("i am tired", "you") << endl;

    return 0;
}

class Solution {
public:
    bool isPrefix(const string &sentence, int start, int end, const string &searchWord) {
        for (int i = 0; i < searchWord.size(); i++) {
            if (start + i >= end || sentence[start + i] != searchWord[i]) {
                return false;
            }
        }
        return true;
    }

    int isPrefixOfWord(string sentence, string searchWord) {
        int n = sentence.size(), index = 1, start = 0, end = 0;
        while (start < n) {
            while (end < n && sentence[end] != ' ') {
                end++;
            }
            if (isPrefix(sentence, start, end, searchWord)) {
                return index;
            }

            index++;
            end++;
            start = end;
        }
        return -1;
    }
};

作者:LeetCode-Solution
链接:https://leetcode.cn/problems/check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence/solution/jian-cha-dan-ci-shi-fou-wei-ju-zhong-qi-pqpu2/
来源: 力扣 (LeetCode)
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