检查字符串是否包含vector<string>值的有效方法？

#include <iostream>
#include <vector>
#include <string>

using namespace std;

bool containsString(const string& longString, const vector<string>& strings) {
    // 将vector<string>中的所有字符串拼接成一个长字符串
    string concatenatedString;
    for (const string& str : strings) {
        concatenatedString += str;
    }

    // 使用KMP算法检查长字符串中是否包含待检查的字符串
    int m = concatenatedString.length();
    int n = longString.length();

    if (n == 0) {
        return true;  // 如果待检查的字符串为空，则认为它是任意字符串的子串
    }

    if (m < n) {
        return false;  // 如果长字符串长度小于待检查的字符串长度，则肯定不是子串
    }

    // 构建前缀表
    vector<int> prefixTable(n, 0);
    int len = 0;
    int i = 1;

    while (i < n) {
        if (longString[i] == longString[len]) {
            len++;
            prefixTable[i] = len;
            i++;
        } else {
            if (len != 0) {
                len = prefixTable[len - 1];
            } else {
                prefixTable[i] = 0;
                i++;
            }
        }
    }

    // 在长字符串中查找待检查的字符串
    int j = 0;
    i = 0;

    while (i < m) {
        if (longString[i] == concatenatedString[j]) {
            i++;
            j++;
        }

        if (j == n) {
            return true;  // 找到了完全匹配，返回true
        } else if (i < m && longString[i] != concatenatedString[j]) {
            if (j != 0) {
                j = prefixTable[j - 1];
            } else {
                i++;
            }
        }
    }

    return false;  // 没有找到完全匹配，返回false
}

int main() {
    string longString = "HelloWorld";
    vector<string> strings = {"Hello", "World"};

    bool result = containsString(longString, strings);
    if (result) {
        cout << "Long string contains all strings in the vector." << endl;
    } else {
        cout << "Long string does not contain all strings in the vector." << endl;
    }

    return 0;
}