Submission #2139091

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Source Code Expand

#include <iostream>
#include <queue>
#include <map>
#include <list>
#include <vector>
#include <string>
#include <stack>
#include <limits>
#include <climits>
#include <cassert>
#include <fstream>
#include <cstring>
#include <cmath>
#include <bitset>
#include <iomanip>
#include <algorithm>
#include <functional>
#include <cstdio>
#include <ciso646>
#include <set>
#include <array>
#include <unordered_map>
#include <complex>

using namespace std;

#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

#define inf 0x3f3f3f3f
#define PB push_back
#define MP make_pair
#define ALL(a) (a).begin(),(a).end()
#define SET(a,c) memset(a,c,sizeof a)
#define CLR(a) memset(a,0,sizeof a)
#define VS vector<string>
#define VI vector<ll>
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define MIN(a,b) (a>b?b:a)
#define MAX(a,b) (a>b?a:b)
#define pi 2*acos(0.0)
#define INFILE() freopen("in0.txt","r",stdin)
#define OUTFILE()freopen("out0.txt","w",stdout)
#define ll long long
#define ull unsigned long long
#define pii pair<ll,ll>
#define pcc pair<char,char>
#define pic pair<ll,char>
#define pci pair<char,ll>
#define eps 1e-14
#define FST first
#define SEC second
#define SETUP cin.tie(0), ios::sync_with_stdio(false), cout << setprecision(15)

namespace {
	struct input_returnner {
		ll N; input_returnner(ll N_ = 0) :N(N_) {}
		template<typename T> operator vector<T>() const { vector<T> res(N); for (auto &a : res) cin >> a; return std::move(res); }
		template<typename T> operator T() const { T res; cin >> res; return res; }
		template<typename T> T operator - (T right) { return T(input_returnner()) - right; }
		template<typename T> T operator + (T right) { return T(input_returnner()) + right; }
		template<typename T> T operator * (T right) { return T(input_returnner()) * right; }
		template<typename T> T operator / (T right) { return T(input_returnner()) / right; }
		template<typename T> T operator << (T right) { return T(input_returnner()) << right; }
		template<typename T> T operator >> (T right) { return T(input_returnner()) >> right; }
	};
	template<typename T> input_returnner in() { return in<T>(); }
	input_returnner in() { return input_returnner(); }
	input_returnner in(ll N) { return std::move(input_returnner(N)); }
}

const ll MOD = 1e9 + 7;

void solve();

signed main() {
	SETUP;
	solve();
#ifdef _DEBUG
	system("pause");
#endif
	return 0;
}

int dp[302][302][301] = {}; // dp[l][r][x] : x個文字列を変更する権利を使用した時に, [l,r)間で最長となる回文

void solve() {
	string S; cin >> S;
	int K; cin >> K;
	REP(i, S.size()) REP(x,K+1){
		dp[i][i + 1][x] = 1;
	}
	FOR(w, 2, S.size()+1) {
		FOR(l, 0, S.size() + 1 - w) {
			FOR(x, 0, K+1) {
				int r = l + w;
				// cout << S[l] << " " << S[r-1] << endl;
				if (S[l] == S[r-1]) {
					dp[l][r][x] = dp[l + 1][r - 1][x] + 2;
				}
				else {
					dp[l][r][x] = max(dp[l + 1][r][x], dp[l][r - 1][x]);
					if(x-1 >= 0) dp[l][r][x] = max(dp[l][r][x], dp[l + 1][r - 1][x - 1] + 2);
				}
			}
		}
	}
	int res = 0;
	REP(i, K+1) {
		res = max(res, dp[0][S.size()][i]);
	}
	cout << res << endl;
}

Submission Info

Judge Result