C++ 代码

#include <iostream>
#include <string>

using namespace std;

int main()
{
    string s;
    int n;
    cin >> s >> n;
    while(n--)
    {
        int l,r;
        string s1,s2;
        cin >> l >> r >> s1 >> s2;
        string cp = s.substr(l-1,r-l+1);
        s.erase(l-1,r-l+1);
        string s3 = s1 + s2;
        size_t pos = s.find(s3);
        if(pos == string::npos)
            s += cp;
        else
            s.insert(pos + s1.size(),cp);
    }
    cout << s;
    return 0;
}