Submission #1307470

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Source Code Expand

using namespace std;
using ll=long long;
#include <string>
#include <vector>
#include <cmath>
#include <iostream>
#include <algorithm>
#define out(S) cout<<(S)<<endl;


int main()
{
	string S;
	cin >> S;
	//後ろから3文字目で判断
	while (S.size()>=5)
	{
		int index = S.size();
		string s = S;
		if (s.substr(index-5,index) == "dream") {
			//dream
			S.erase(index - 5, index);
		}
		else if (index>=7&&s.substr(index-7,index)=="dreamer") {
			//dreamer
			S.erase(index-7, index);
		}
		else if (s.substr(index-5,index)=="erase") {
			//erase
			S.erase(index - 5, index);
		}
		else if (index>=6&&s.substr(index-6,index)=="eraser") {
			//eraser
			S.erase(index - 6, index);
		}
		else {
			break;
		}
	}
	if (S.size() == 0) {
		out("YES");
	}
	else {
		out("NO");
	}
	return 0;
}

Submission Info

Judge Result