给定两字符串S1和S2，若s1删除若干字符后能成为s2，则s1为s2的字串，找出s2在s1中起始位置最大值C++

以下是C++的实现代码：

#include <iostream>
#include <string>
using namespace std;

int find_starting_position(string s1, string s2) {
    int i = 0, j = 0, start = -1;
    while (i < s1.length()) {
        if (s1[i] == s2[j]) {
            j += 1;
            if (j == s2.length()) {
                start = i - j + 1;
                j = 0;
            }
        } else {
            j = 0;
        }
        i += 1;
    }
    return start;
}

int main() {
    string s1 = "hello world";
    string s2 = "world";
    int start = find_starting_position(s1, s2);
    if (start == -1) {
        cout << "s2 is not a substring of s1" << endl;
    } else {
        cout << "s2 starts at position " << start << " in s1" << endl;
    }
    return 0;
}

注意：这里的起始位置是从0开始计数的，如果返回-1表示s2不是s1的子串。