add better solution to old task to test gpt-4

Author: optozorax

contests/icpc/acm2018/5_new2.cpp

@@ -0,0 +1,84 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+#include <sstream>
+
+using namespace std;
+
+void test(string str) {
+	string* str1 = new string(str);
+	istringstream* iss = new istringstream(*str1);
+	cin.rdbuf(iss->rdbuf());
+}
+
+vector<vector<bool>> is_filled;
+vector<vector<bool>> is_delete; // is_delete[i][j] означает, можно ли удалить символы с i по j в строке
+string str;
+bool get_can_delete(int i, int j) {
+	if (i > j) throw exception();
+	if (is_filled[i][j]) return is_delete[i][j];
+	if (i == j) return false;
+
+	auto len = j - i + 1;
+
+	bool result = false;
+	if (str[i] == str[j]) {
+		if (len == 2 || len == 3) result = true;
+		if (len >= 4) result |= get_can_delete(i+1, j-1);	
+		if (len >= 5) {
+			result |= get_can_delete(i+1, j-2);
+			result |= get_can_delete(i+2, j-1);
+			for (int k = i+1; k < j-2; ++k) {
+				if (get_can_delete(i+1, k) && get_can_delete(k+2, j-1)) {
+					result = true;
+					break;
+				}
+			}
+		}
+	}
+	for (int k = i; k < j; ++k) {
+		if (get_can_delete(i, k) && get_can_delete(k+1, j)) {
+			result = true;
+			break;
+		}
+	}
+
+	is_filled[i][j] = true;
+	is_delete[i][j] = result;
+	return result;
+}
+
+int findMax(void) {
+	vector<int> max_pos(str.size(), 0);
+	for (int i = 0; i < str.size(); ++i) {
+		int end = str.size() - 1;
+		int pos = end - i;
+		if (get_can_delete(pos, end))
+			max_pos[pos] = i+1;
+		else {
+			if (pos != end) max_pos[pos] = max_pos[pos+1];
+			for (int j = 0; j < i; ++j) {
+				if (get_can_delete(pos, pos + j)) {
+					max_pos[pos] = max(max_pos[pos], j+1 + max_pos[pos + j+1]);
+				}
+			}
+		}
+	}
+	return max_pos[0];
+}
+
+int main() {
+	//test("abcdccb");
+	//test("abbccad");
+	//test("abcdcba");
+	//test("aaaerttew");
+	//test("cbcettre");
+	test("hhaghaeahhhibihcffhecehcgahdabaahcdfghgfdbgadjdh"); // ответ 8
+	// test("awwbereare"); // ответ 2
+	//test("faaghbfdahgeeheddcedfcgabdecgadgefeaachdecbbhgedgeabegdedaefdbfgcdcaeccaafahhfhbdgdhfhdhdbgdfffdbfafhaafchabacedgdfhdddafgebbacdcheededdbfgddbfcaccghggbbedhcbbgfdhggheabebeaagddgcgafahggfebfbcbccgbdebhdeehhchfahdbdcccghecdhbfeehehgdebhhbfddeafdbghffecehhcbdgcbhbfdgbgdchddagafgbbefahhhchcccbdfdcagcebbbcghdbbedbhfcddhehfddachfbdgafgbebadfccagdedaggcehffbgdfeehbadegcadccdgbfehgdghhfdebadhhbgafgefgdgddahghdegggagfhgbeceddegegfcceeceffgfdhbhfcfghfeehfedchfhchchgcedbebbhbgebgceceagcecfahhgdecefhacdcddbaghfceecggahhagafhccegeghchcaedahdhfehgbedddaghcccdhcfagafbefhgafeebdggcchhedabhccgdcaadfhbdccabddfggdhdacdbadfddbcbfacdhgdfcabahagcchgbafgcabgbahededhahedabaaaeeeghhdcefhbhaghbedbabdgfcadehchgbgecdhhachcaacaafefagbdghffaadabfdhedeehbccfbdcacabbbbaadbfchfdehccabgghdfehfggbhhghecbheebfbhfcefegdgfccaacedghhgebaegcbgcafgfeaabghbefbaacgggbeehbecfaheeefcadaecfgfchchfcccbafgeddagccebfhbhchfbhhbdhffadaghhbedfghcfgghaeedcacfceffddbhgcdccgdahdcabhbbchfadgcahddcfcaefgbgfehbbdcdggfhfaafgaefhhhdcebgcefccdc"); // ответ 175
+
+	cin >> str;
+	is_filled = vector<vector<bool>>(str.size(), vector<bool>(str.size(), false));
+	is_delete = vector<vector<bool>>(str.size(), vector<bool>(str.size(), false));
+	cout << str.size() - findMax();
+}