C++ 代码

#include <string.h>
#include <iostream>
#include <string>

using std::cout;
using std::cin;
using std::endl;
using std::string;

string CUT(const string& original,int l, 
           int r, string& clipBoard){
    string res;
    res = original.substr(0,l) + original.substr(r+1);
    clipBoard = original.substr(l,r-l+1);
    return res;
}

string COPY(const string& original, int l,
            int r, string& clipBoard){
    clipBoard = original.substr(l,r-l+1);
    return original;
}

string PASTE(const string& original, int l, 
             int r, string& clipBoard){
    string res = original.substr(0,l+1)
        + clipBoard 
        + original.substr(l+1);
    return res;
}

int main()
{
    string original;
    cin >> original;

    int n;
    cin >> n;

    string clipBoard;   // 初始剪切板为空
    for(int i = 0; i < n; i++){
        string op;
        int l;
        int r;
        cin >> op;

        if(op == "CUT"){
            cin >> l >> r;
            original = CUT(original,l,r,clipBoard);       
        }else if(op == "COPY"){
            cin >> l >> r;
            original = COPY(original,l,r,clipBoard);
        }else{
            cin >> l;
            original = PASTE(original,l,r,clipBoard);
        }
        cout << original << endl;
    }

    return 0;
}