日常训练2025-1-2
D. Digital string maximization
rating:1300
https://codeforces.com/contest/2050/problem/D
思路：找trick + 暴力
根据题意，一个数值为 i 的数最多向左移动 i 步。而最大的数为 9 ，也就是说对于一个位置 x ，他的值只可能来自于 \([x, x + 9]\) 这个范围，更远的那些数不可能移动过来
所以即使是暴力时间复杂度也不过是\(O(9*n)\)
评述
好烦这道题！！
代码
#include <bits/stdc++.h>typedef std::pair<int, int> pii;
#define INF 0x3f3f3f3f
#define MOD 998244353
using i64 = long long;
const int N = 1e5+5;void solve(){std::string s;std::cin >> s;int n = s.size();for (int i = 0; i < n; i++){int cur = s[i] - '0';int pos = -1;for (int j = i; j < n && j < i + 10; j++){if (s[j] - '0' - j + i > cur){pos = j;cur = s[j] - '0' - j + i;}}if (pos != -1){for (int k = pos; k >= i + 1; k--){s[k]--;std::swap(s[k], s[k-1]);}}}std::cout << s << '\n';
}signed main()
{std::ios::sync_with_stdio(false);std::cin.tie(nullptr);std::cout<<std::setiosflags(std::ios::fixed)<<std::setprecision(2);int t = 1, i;std::cin >> t;for (i = 0; i < t; i++){solve();}return 0;
}
B. pspspsps
rating:1300
https://codeforces.com/problemset/problem/2049/B
思路（找trick）
直接找规律吧，没啥其他方法
代码
#include <bits/stdc++.h>
using namespace std;
using i64 = long long;#if !defined(ONLINE_JUDGE) && defined(LOCAL)
#include "helper.h"
bool IS_LOCAL = true;
#else
#define dbg(...) ;
bool IS_LOCAL = false;
#endifvoid go() {int n;string s;cin >> n >> s;if (n == 1) {cout << "YES" << endl;} else if (!s.contains('s') || !s.contains('p')) {cout << "YES" << endl;} else if (s[0] == 's' && !s.substr(1, s.size() - 1).contains('s')) {cout << "YES" << endl;} else if (s[n - 1] == 'p' && !s.substr(0, n - 1).contains('p')) {cout << "YES" << endl;} else {cout << "NO" << endl;}
}int main() {ios::sync_with_stdio(false);cin.tie(nullptr);if (IS_LOCAL)std::cout << std::unitbuf;for (int batch = 1;; batch++) {int caseCnt;cin >> caseCnt;if (!caseCnt || cin.fail())break;for (int i = 1; i <= caseCnt; i++) {dbg(batch, i);go();}}return 0;
}
