Algo Study

Author: CSKIM999

.DS_Store

@@ -2,4 +2,5 @@ SK_2.py
 line.py
 CT_folder
 text.txt
-tech-interview-for-developer
+tech-interview-for-developer
+.cph

.gitignore

@@ -0,0 +1,15 @@
+ipt = []
+n = int(input())
+for _ in range(n):
+    ipt.append(int(input()))
+M = max(ipt)
+dp = [0]*(M+1)
+dp[1] = 1
+dp[2] = 2
+dp[3] = 4
+
+if M >=4:
+    for i in range(4,M+1):
+        dp[i] = (dp[i-1] + dp[i-2] + dp[i-3])%1000000009
+for i in ipt:
+    print(dp[i])

1_2_3_더하기_3.py

@@ -257,7 +257,7 @@ def xprint(a):
 꺼내는 속도를 더욱 더 빠르게 하기위해 queue 를 써볼까 한다
 '''
 
-# from collections import deque
+# from collections import dequer
 
 # def Csort(lst):
 #     counting = [[i,0] for i in range(101)]

BOJ_/Solved/BOJ_2.py

@@ -0,0 +1,44 @@
+from collections import deque
+def solution(n, wires):
+    i = 0
+    table = [[] for _ in range(n)]
+    answer = 1e9
+    for i,j in wires:
+        i,j = i-1,j-1
+        table[i].append(j)
+        table[j].append(i)
+    
+    for i in range(n-1):
+        a,b = wires[i]
+        a -=1
+        b -=1
+        table[a].remove(b)
+        table[b].remove(a)
+        link = [None for _ in range(n)]
+        for j in range(n):
+            now = link[j]
+            q = deque()
+            if now == None:
+                link[j] = j
+                for k in table[j]:
+                    q.append(k)
+                while q:
+                    new = q.popleft()
+                    if link[new] == None:
+                        link[new] = j
+                        for k in table[new]:
+                            q.append(k)
+        c,d = min(link),max(link)
+        cc,dc = link.count(c),link.count(d)
+        print(link)
+        print(c,d)
+        print(cc,dc)
+        cal = abs(cc-dc)
+        answer = min(cal,answer)
+        table[a].append(b)
+        table[b].append(a)
+    return answer
+
+n = 7
+wires = [[1, 2], [2, 7], [3, 7], [3, 4], [4, 5], [6, 7]]
+solution(n,wires)

H-index.py

@@ -0,0 +1,51 @@
+'''
+case 1
+증가라면 무조건 증가수열밖에 없음
+case 2
+감소라면 무조건 감소수열밖에 없음
+
+바꿔줘야한다면 0 index 값이 최대 혹은 최솟값이어야함.
+쭉 체크하다가 증가하면 증가수열 플래그 감소하면 감소수열 플래그
+
+'''
+import heapq
+heapq.heapify
+n = int(input())
+data = list(map(int,input().split()))
+b4 = data[0]
+uf,df = 0,0
+us,ds = 0,0
+swap = 0
+for i in range(1,n):
+    now = data[i]
+    if us:
+        if b4 > now or now > data[0]:
+            us = -1
+        b4 = now
+    if ds:
+        if bf < now or now < data[0]:
+            ds = -1
+        b4 = now
+    if not us and not ds:
+        break
+
+    if uf and not us:
+        if now < b4:
+            uf = i
+            us = i
+    else:
+        if b4 == now:
+            continue
+        elif b4 < now:
+            uf = i
+    if df and not ds:
+        if now > b4:
+            bf = i
+            ds = i
+    else:
+        if b4 == now:
+            continue
+        else:
+            bf = i
+    b4 = now
+print(us,ds)