2022-7-18 summary

The time for this summary is 2022-7-16~2022-7-18

These two days are mainly in question brushing training ：

Niuke supplement ：

 

 

CF Supplementary questions ：

5.00 Summer vacation Niuke adds supplementary questions ：

 

/*
https://ac.nowcoder.com/acm/contest/33186/I
Chiitoitsu
*/

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int mod = 1e9 + 7;
int n;
int dp[20][200];
int ksm(int a, int b) {
    int ret = 1;
    while (b) {
        if (b & 1) {
            ret *= a;
            ret %= mod;
        }
        a = a * a;
        a %= mod;
        b >>= 1;
    }
    return ret;
}
int inv(int a) { return ksm(a, mod - 2); }

int mul(int a, int b) { return a * b % mod; }
void solve(int c) {
    // memset(dp, 1, sizeof dp);
    for (int i = 6; i >= 0; i--) {
        for (int j = 1; j <= 136; j++) {
            dp[i][j] = 1;
            int ok   = (13 - 2 * i) * 3;
            dp[i][j] = dp[i][j] + mul(dp[i][j - 1], mul(j - ok, inv(j)));
            dp[i][j] %= mod;
            if (i != 6) { dp[i][j] = dp[i][j] + mul(dp[i + 1][j - 1], mul(ok, inv(j))); }
            dp[i][j] %= mod;
        }
    }
    string s;
    cin >> s;
    int cnt = 0;
    std::map<string, int> mp;
    for (int i = 0; i < 25; i += 2) {
        string tmp = "";
        tmp += s[i];
        tmp += s[i + 1];
        mp[tmp]++;
        if (mp[tmp] == 2) { cnt++; }
    }
    // cout << cnt << endl;
    printf("Case #%d: %ld\n", c, dp[cnt][123]);
    return;
}


signed main() {
    int T;
    cin >> T;
    for (int i = 1; i <= T; i++) { solve(i); }
    return 0;
}

This is a wrong topic , This probability DP, At first, it was （7-i） The number of cards is not considered , Consider logarithm directly , Not paying attention to , What a injustice , Another topic is

 

 

  Write a wrong symbol , After a long time .... In a word, I didn't pay attention to the details , Then I returned the sample and 37.5%, Outrageous . Play well tomorrow .