Codeforces Round #740 (Div. 2, based on VK Cup 2021 - Final (Engine))

Posted 2021-09-10 Jozky86

Codeforces Round #740 (Div. 2, based on VK Cup 2021 - Final (Engine))

题号	题目	知识点
A	Simply Strange Sort	暴力
B	Charmed by the Game
C	Deep Down Below
D1	Up the Strip (simplified version)
D2	Up the Strip
E	Bottom-Tier Reversals
F	Top-Notch Insertions

A

直接暴力就行，n才999

// Problem: A. Simply Strange Sort
// Contest: Codeforces - Codeforces Round #740 (Div. 2, based on VK Cup 2021 - Final (Engine))
// URL: https://codeforces.com/contest/1561/problem/A
// Memory Limit: 512 MB
// Time Limit: 2000 ms
// Data:2021-08-24 22:38:22
// By Jozky

#include <bits/stdc++.h>
#include <unordered_map>
#define debug(a, b) printf("%s = %d\\n", a, b);
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
clock_t startTime, endTime;
//Fe~Jozky
const ll INF_ll= 1e18;
const int INF_int= 0x3f3f3f3f;
void read(){};
template <typename _Tp, typename... _Tps> void read(_Tp& x, _Tps&... Ar)
{
    x= 0;
    char c= getchar();
    bool flag= 0;
    while (c < '0' || c > '9')
        flag|= (c == '-'), c= getchar();
    while (c >= '0' && c <= '9')
        x= (x << 3) + (x << 1) + (c ^ 48), c= getchar();
    if (flag)
        x= -x;
    read(Ar...);
}
template <typename T> inline void write(T x)
{
    if (x < 0) {
        x= ~(x - 1);
        putchar('-');
    }
    if (x > 9)
        write(x / 10);
    putchar(x % 10 + '0');
}
void rd_test()
{
#ifdef LOCAL
    startTime= clock();
    freopen("in.txt", "r", stdin);
#endif
}
void Time_test()
{
#ifdef LOCAL
    endTime= clock();
    printf("\\nRun Time:%lfs\\n", (double)(endTime - startTime) / CLOCKS_PER_SEC);
#endif
}
const int maxn= 2000;
int a[maxn];
int main()
{
    //rd_test();
    int t;
    read(t);
    while (t--) {
        int n;
        read(n);
        memset(a, 0, sizeof(a));
        for (int i= 1; i <= n; i++)
            read(a[i]);
        bool f= 1;
        for (int i= 1; i < n; i++) {
            if (a[i] > a[i + 1]) {
                f= 0;
                break;
            }
        }
        if (f == 1) {
            printf("0\\n");
            continue;
        }
        for (int i= 1;; i++) {
            if (i & 1) { //如果i是奇数
                for (int j= 1; j < n; j+= 2) {
                    if (a[j] > a[j + 1])
                        swap(a[j], a[j + 1]);
                }
            }
            else {
                for (int j= 2; j < n; j+= 2) {
                    if (a[j] > a[j + 1])
                        swap(a[j], a[j + 1]);
                }
            }
            bool f= 1;
            for (int j= 1; j < n; j++) {
                if (a[j] > a[j + 1]) //存在逆序
                {
                    f= 0;
                    break;
                }
            }
            if (f) {
                printf("%d\\n", i);
                break;
            }
        }
    }
    return 0;
    //Time_test();
}