2023CSP-J游寄

没话说了，S组没进复赛，只能打J组，J组打的也是一团糟。。

过程

上午8:10

进考场了，打开vscode写模板

上午8:25

密码发下来了，开始解压，喝口水压压惊.

开始浏览题目，看到T3我又惊了（又是一元二次方程，CCF这么喜欢一元二次吗？）。

上午8:30

开始比赛了。

T1一眼思维题，便开始推导思路。

上午9:20

T1找规律找不下去了，就本着正解和暴力只差10pts的原则，打了暴力，骗了90pts。

赛时T1代码

赛时的代码就是暴力，暴力，暴力，当时没有想到正解。。。

#include
using namespace std;
long long n, l, f[10000005], cnt, a[10000005], k;
int main() {
	freopen("apple.in", "r", stdin);
	freopen("apple.out", "w", stdout);
	cin >> n;
	for (k = 1;; k++) {
		l++, cnt = 0;
		bool flag = false;
		for (int i = 1; i <= n; i++) {
			if (f[i] == 0) {
				flag = true;
				break;
			}
		}
		if (flag == false) {
			break;
		}
		for (int i = 1; i <= n; i++) {
			if (f[i] != 1) {
				++cnt;
				if (cnt % 3 == 1) {
					a[i] = l;
					f[i] = 1;
				}
			}
		}
	}
	cout << k - 1 << " " << a[n] << "\n";
	return 0;
}

发现时间不多了，立马开始看T2，一眼贪心。

上午9:30

T2知道了怎么做，就是找下降子序列。

上午9:50

T2打完了，当时脑子抽了，打了前缀和+离散化+贪心，大样例过了，便心安了。

T2赛时代码
wssb，打了一大堆东西，后来缩减一下就A了！

#include
using namespace std;
long long n, d, v[100005], t[100005];
long long pre, q[100005], ans, dis;
double oil;
struct node {
	long long id, val;
	friend bool operator<(node x, node y) {
		return x.val < y.val;
	}
} a[100005];
int main() {
	freopen("road.in", "r", stdin);
	freopen("road.out", "w", stdout);
	cin >> n >> d;
	for (int i = 1; i < n; i++) {
		cin >> v[i];
	}
	for (int i = 1; i <= n; i++) {
		cin >> a[i].val;
		q[i + 1] = q[i] + v[i];
		t[i] = a[i].val;
	}
	sort(t + 1, t + n + 1);
	for (int i = 1; i <= n; i++) {
		long long j = lower_bound(t + 1, t + n + 1, a[i].val) - t;
		a[i].id = j;
	}
	for (int i = 1; i <= n;) {
		oil -= dis * 1.0 / d;
		for (int j = i + 1; j <= n; j++) {
			if (j == n) {
				dis = q[j] - q[i];
				ans += ((long long)ceil(dis * 1.0 / d - oil)) * a[i].val;
				cout << ans;
				return 0;
			}
			if (a[j].id < a[i].id) {
				dis = q[j] - q[i];
				ans += ((long long)ceil(dis * 1.0 / d - oil)) * a[i].val;
				oil += ceil(dis * 1.0 / d);
				i = j, pre = i;
				break;
			}
		}
	}
	return 0;
}

开始看T3，一眼大模拟。

上午10:30

大模拟打完了，大样例没过，开始调试。但不知道为什么考场的那个vscode调试不了，于是就只能手动输出过程。

上午11:50

调试了半天，大样例终于过了，Ctrl+S保存了代码。

T3赛时代码
有点多，大模拟

#include
using namespace std;
int n, up, a, b, c;
int main() {
	freopen("uqe.in", "r", stdin);
	freopen("uqe.out", "w", stdout);
	cin >> n >> up;
	for (int t = 1; t <= n; t++) {
		cin >> a >> b >> c;
		int derta = b * b - 4 * a * c;
		if (derta < 0) {
			cout << "NO\n";
		} else {
			int tmpb = -b, tmpm = 2 * a;
			if (b == 0) {
				if (tmpm > 0) {
					int d = tmpm * tmpm;
					if (derta == d) {
						cout << 1 << "\n";
					} else {
						int s = derta / __gcd(derta, d);
						int m = d / __gcd(derta, d);
						int mod = 1;
						for (int j = sqrt(s * m); j >= 2; j--) {
							if ((s * m) % (j * j) == 0) {
								mod = j;
								break;
							}
						}
						cout << mod << "\n";
						if (mod == 1) {
							cout << "sqrt(" << s*m << ")";
							if (m != 1) {
								cout << "/" << m;
							}
							cout << "\n";
						} else {
							cout << mod << "*sqrt(" << s*m / mod / mod << ")";
							if (m != 1) {
								cout << "/" << m;
							}
							cout << "\n";
						}

					}
				} else {
					int d = tmpm * tmpm;
					if (derta == d) {
						cout << 1 << "\n";
					} else {
						int s = derta / __gcd(derta, d);
						int m = c / __gcd(derta, d);
						cout << "-sqrt(" << s*m << ")/" << m << "\n";
					}
				}
				continue;
			} else {
				if (sqrt(derta)*sqrt(derta) == derta) {
					int son = tmpb + sqrt(derta);
					if (son == 0) {
						cout << 0;
					} else if (son > 0 && tmpm > 0 || son < 0 && tmpm < 0) {
						int son2 = abs(tmpb - sqrt(derta));
						if (son < 0) {
							son2 = abs(son2);
							tmpm = abs(tmpm);
							int mod = 1;
							for (int j = sqrt(derta); j >= 2; j--) {
								if (derta % (j * j) == 0) {
									mod = j;
									break;
								}
							}
							if (son2 % tmpm == 0) {
								cout << son2 / tmpm << "\n";
							} else {
								cout << son2 / __gcd(son2, tmpm) << "/" << tmpm / __gcd(son2, tmpm) << "\n";
							}
						} else {
							son = abs(son);
							tmpm = abs(tmpm);
							int mod = 1;
							for (int j = sqrt(derta); j >= 2; j--) {
								if (derta % (j * j) == 0) {
									mod = j;
									break;
								}
							}
							if (son % tmpm == 0) {
								cout << son / tmpm << "\n";
							} else {
								cout << son / __gcd(son, tmpm) << "/" << tmpm / __gcd(son, tmpm) << "\n";
							}
						}
					} else {
						int son2 = tmpb - sqrt(derta);
						if (son2 > 0 && tmpm > 0 || son2 < 0 && tmpm < 0) {
							son2 = abs(son2);
							tmpm = abs(tmpm);
							int mod = 1;
							for (int j = sqrt(derta); j >= 2; j--) {
								if (derta % (j * j) == 0) {
									mod = j;
									break;
								}
							}
							if (son2 % tmpm == 0) {
								cout << son2 / tmpm << "\n";
							} else {
								cout << son2 / __gcd(son2, tmpm) << "/" << tmpm / __gcd(son2, tmpm) << "\n";
							}
						} else {
							son = abs(son);
							son2 = abs(son2);
							tmpm = abs(tmpm);
							int mod = 1;
							for (int j = sqrt(derta); j >= 2; j--) {
								if (derta % (j * j) == 0) {
									mod = j;
									break;
								}
							}
							if (son2 * 1.0 / tmpm > son * 1.0 / tmpm) {
								if (son2 % tmpm == 0) {
									cout << "-" << son2 / tmpm << "\n";
								} else {
									cout << "-" << son2 / __gcd(son2, tmpm) << "/" << tmpm / __gcd(son2, tmpm) << "\n";
								}
							} else {
								if (son % tmpm == 0) {
									cout << "-" << son / tmpm << "\n";
								} else {
									cout << "-" << son / __gcd(son, tmpm) << "/" << tmpm / __gcd(son, tmpm) << "\n";
								}
							}
						}

					}
					continue;
				} else {
					if (tmpm < 0) {
						if (tmpb < 0) {
							if (abs(tmpb) % abs(tmpm) != 0) {
								int g = __gcd(abs(tmpb), abs(tmpm));
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << abs(tmpb) / g << "/" << abs(tmpm) / g << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							} else {
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << abs(tmpb) / abs(tmpm) << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							}
							continue;
						} else {
							if (abs(tmpb) % abs(tmpm) != 0) {
								int g = __gcd(abs(tmpb), abs(tmpm)), mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								if (mod % abs(tmpm) == 0) {
									cout << "-" << abs(tmpb) / g << "/" << abs(tmpm) / g << "+sqrt(" << derta / mod / mod << ")/" << mod / abs(tmpm) << "\n";
								} else {
									if (mod != 1) {
										cout << "-" << abs(tmpb) / g << "/" << abs(tmpm) / g << "+" << mod << "*sqrt(" << derta / mod / mod << ")/" << abs(tmpm) << "\n";
									}
									cout << "-" << abs(tmpb) / g << "/" << abs(tmpm) / g << "sqrt(" << derta / mod / mod << ")/" << abs(tmpm) << "\n";
								}
							} else {
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << "-" << abs(tmpb) / abs(tmpm) << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							}
							continue;
						}
					} else {
						if (tmpb < 0) {
							if (abs(tmpb) % abs(tmpm) != 0) {
								int g = __gcd(abs(tmpb), abs(tmpm));
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << "-" << abs(tmpb) / g << "/" << abs(tmpm) / g << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							} else {
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << "-" << abs(tmpb) / abs(tmpm) << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							}
							continue;
						} else {
							if (abs(tmpb) % abs(tmpm) != 0) {
								int g = __gcd(abs(tmpb), abs(tmpm));
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << abs(tmpb) / g << "/" << abs(tmpm) / g << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							} else {
								int mod = 1;
								for (int j = sqrt(derta); j >= 2; j--) {
									if (derta % (j * j) == 0) {
										mod = j;
										break;
									}
								}
								cout << abs(tmpb) / abs(tmpm) << "+sqrt(" << derta << ")/" << abs(tmpm) << "\n";
							}
							continue;
						}
					}
				}
			}
		}
	}
	return 0;
}

开始看T4，虽然只有10min了，但是发现T4输出-1有分，于是就花1min打了一个-1。

中午12:00

考试结束了，如释重负，走出考场闻闻新鲜空气。

晚上8:30

满怀激动的来洛谷测，以为这次300+pts胜券在握。

晚上8:35

T1->90pts理所应当
T2->45pts 大样例都过了，不知道这次是不是有个地方考虑漏了，希望CCF的数据和大样例一样水。。。
T3->0pts 震惊到我了，好说歹说也应该至少50pts啊，我仔细检查了一下自己的代码，调试过程没删！！！我当场晕了过去。。
T4->0pts 理所应当

结果

洛谷上测出来145pts，跟估分差了十万八千里。

估分：90+100+100+[10,20]=[300,310]pts

实际：90+45+0+10=145pts

T3报灵了，全部都因为没有删去调试的中间过程，艹。

后寄

没什么好说，这次寄了，如果到明年都不会away from OI，希望明年不要犯如此低级的错误。。。