2022.4.10周學習總結

阿新 • • 發佈：2022-04-10

一、本週學習進度

　　1.java開始寫專案了，資料庫連線也建好了。

　　2.郵箱傳送的功能已經寫好了

　　3.登入功能寫好了

4.註冊功能還差一點點就寫好了

二、本週打比賽及補題情況

1.cf781div2（比賽的時候只寫了兩道題，補題的時候補了一道)

C題當時有思路但是wa了，沒寫出來，賽後看別人題解，學了一手別人的二分。然後補了出來

程式碼實現

 1 #include <iostream>
 2 #include <queue>
 3 #include <vector>
 4 #include <cstring>
 5 #include <string>
 6 #include <map>
 7 #include <cmath>
 8 #include <algorithm>
 9 #include <set>
10 #include <stack>
11 #include <cstdio>
12 #include <climits>
13 #define PII pair<int,int>
14 #define rep(i,z,n) for(int i = z;i <= n; i++)
15 #define per(i,n,z) for(int i = n;i >= z; i--)
16 #define ll long long
17 #define db double
18 #define vi vector<int>
19 #define debug(x) cerr << "!!!" << x << endl;
20 using namespace std;//
21 inline ll read()
22 {
23     ll s,r;
24     r = 1;
25     s = 0;
26     char ch = getchar();
27     while(ch < '0' || ch > '9'){
28         if(ch == '-')
29             r = -1;
30         ch = getchar();
31     }
32     while(ch >= '0' && ch <= '9'){
33         s = (s << 1) + (s << 3) + (ch ^ 48);
34         ch = getchar();
35     }
36     return s * r;
37 }
38 inline void write(ll x)
39 {
40     if(x < 0) putchar('-'),x = -x;
41     if(x > 9) write(x / 10);
42     putchar(x % 10 + '0');
43 }
44 int a[200010];
45 int fa[200010];
46 bool vis[200010];
47 bool check(int val,vector <int> &tmp)
48 {
49     int cnt = 0;
50     for(int i = 0,len = tmp.size();i < len;i++){
51         cnt++;
52         cnt += max(0,tmp[i] - (val - i));
53     }
54     // cout << cnt << endl;
55     return cnt <= val;
56 }
57 bool cmp(int p,int k)
58 {
59     return p > k;
60 }
61 int main()
62 {
63     int t;
64     cin >> t;
65     while(t--){
66         int n;
67         memset(fa,0,sizeof(fa));
68         memset(vis,0,sizeof(vis));
69         vector <int> tmp;
70         //fa[0]++;
71         tmp.push_back(1);
72         scanf("%d",&n);
73         rep(i,1,n - 1) {
74             cin >> a[i];
75             fa[a[i]]++;
76         }
77         rep(i,0,n) if(fa[i]) tmp.push_back(fa[i]);
78         sort(tmp.begin(),tmp.end(),cmp);
79         int l,r;
80         l = 1;
81         r = n;
82         int ans = INT_MAX;
83         while(l <= r){
84             int m = (l + r) >> 1;
85             if(check(m,tmp)){
86                 ans = min(ans,m);
87                 r = m - 1;
88             }
89             else
90                 l = m + 1;
91         }
92         cout << ans << endl;
93     }
94     return 0;
95 }

2.cfedu126（比賽的時候只寫了兩道題，補題的時候補了一道)

感覺狀態有點拉跨，打比賽的時候有點累。思路也很死。

補了一下C題，又是一個二分，還是不會。學了一手別人的二分，看了半天才看懂別人的程式碼。

 1 #include <iostream>
 2 #include <queue>
 3 #include <vector>
 4 #include <cstring>
 5 #include <string>
 6 #include <map>
 7 #include <cmath>
 8 #include <algorithm>
 9 #include <set>
10 #include <stack>
11 #include <cstdio>
12 #include <climits>
13 #define PII pair<int,int>
14 #define rep(i,z,n) for(int i = z;i <= n; i++)
15 #define per(i,n,z) for(int i = n;i >= z; i--)
16 #define ll long long
17 #define db double
18 #define vi vector<int>
19 #define debug(x) cerr << "!!!" << x << endl;
20 using namespace std;
21 inline ll read()
22 {
23     ll s,r;
24     r = 1;
25     s = 0;
26     char ch = getchar();
27     while(ch < '0' || ch > '9'){
28         if(ch == '-')
29             r = -1;
30         ch = getchar();
31     }
32     while(ch >= '0' && ch <= '9'){
33         s = (s << 1) + (s << 3) + (ch ^ 48);
34         ch = getchar();
35     }
36     return s * r;
37 }
38 inline void write(ll x)
39 {
40     if(x < 0) putchar('-'),x = -x;
41     if(x > 9) write(x / 10);
42     putchar(x % 10 + '0');
43 }
44 bool cmp(int p,int k)
45 {
46     return p > k;
47 }
48 ll a[300010];
49 int n;
50 ll ans;
51 ll check(int val)
52 {
53     ll c1 = 0;
54     ll c2 = 0;
55     rep(i,1,n) {
56         c1 += (val - a[i]) % 2;
57         c2 += (val - a[i]) / 2; 
58     }
59     ll c = 0;
60     if(c2 >= c1 + 2)
61         c = (c2 - c1 - 2) / 3 + 1;
62     return max((c1 + 2 * c) * 2 - 1,(c2 - c) * 2); 
63 }
64 int main()
65 {
66     int t;
67     ios::sync_with_stdio(false);
68     cin >> t;
69     while(t--){
70         cin >> n;
71         ll mk = -1;
72         ans = 1e18;
73         rep(i,1,n) {
74             cin >> a[i];
75             mk = max(mk,a[i]);
76         }
77         rep(i,0,1) ans = min(ans,check(mk + i));
78         cout << ans << endl;
79     }
80     return 0;
81 }