[권혁준-13주차 알고리즘 스터디]

권혁준_13주차/[BOJ-10266] 시계 사진들.md

@@ -0,0 +1,80 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+class Main {
+
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+
+	static int N;
+	static int[] A, B;
+	static int[] X;
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+
+	}
+
+	static void ready() throws Exception{
+
+		N = nextInt();
+		A = new int[2*N-1];
+		B = new int[N];
+		X = new int[N];
+		int[] ta = new int[N];
+		int[] tb = new int[N];
+		for(int i=0;i<N;i++) ta[i] = nextInt();
+		for(int i=0;i<N;i++) tb[i] = nextInt();
+		Arrays.sort(ta);
+		Arrays.sort(tb);
+		for(int i=1;i<N;i++) A[i-1] = ta[i] - ta[i-1];
+		A[N-1] = 360000+ta[0] - ta[N-1];
+		for(int i=N;i<2*N-1;i++) A[i] = A[i%N];
+		for(int i=1;i<N;i++) B[i-1] = tb[i] - tb[i-1];
+		B[N-1] = 360000+tb[0] - tb[N-1];
+
+	}
+
+	static void solve() throws Exception{
+
+		for(int i=1;i<N;i++){
+		    X[i] = X[i-1];
+		    while(X[i]>0 && B[X[i]] != B[i]) X[i] = X[X[i]-1];
+		    if(B[X[i]] == B[i]) X[i]++;
+		}
+
+		for(int i=0,j=0;i<A.length;i++){
+		    while(j>0 && B[j] != A[i]) j = X[j-1];
+		    if(B[j] == A[i]) j++;
+		    if(j == N) {
+		        bw.write("possible");
+		        return;
+		    }
+		}
+		bw.write("impossible");
+
+	}
+
+}
+
+```

권혁준_13주차/[BOJ-1507] 궁금한 민호.md

@@ -0,0 +1,106 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+
+class Main {
+
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+
+	static int N;
+	static List<int[]> E;
+	static int[] r;
+	static int[][] V;
+
+	static final int INF = 123456789;
+
+	static int f(int x) {return x==r[x] ? x : (r[x]=f(r[x]));}
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+
+	}
+
+	static void ready() throws Exception{
+
+		N = nextInt();
+		E = new ArrayList<>();
+		r = new int[N];
+		V = new int[N][N];
+		for(int i=0;i<N;i++) {
+			r[i] = i;
+			for(int j=0;j<N;j++) {
+				int a = nextInt();
+				if(j>i) E.add(new int[] {i,j,a});
+			}
+		}
+
+	}
+
+	static void solve() throws Exception{
+
+		int ans = 0, cnt = 0;
+		Collections.sort(E, (a,b) -> a[2]-b[2]);
+
+		for(int[] e:E) {
+			int a = e[0], b = e[1], c = e[2];
+			int x = f(a), y = f(b);
+			if(x != y) {
+				V[a][b] = V[b][a] = c;
+				r[x] = y;
+				ans += c;
+				cnt++;
+				continue;
+			}
+
+			int dist = shortestPath(a, b);
+			if(c < dist) {
+				V[a][b] = V[b][a] = c;
+				ans += c;
+			}
+			if(c > dist) {
+				bw.write("-1");
+				return;
+			}
+		}
+
+		if(cnt < N-1) bw.write("-1");
+		else bw.write(ans + "\n");
+
+	}
+
+	static int shortestPath(int start, int end) {
+		int[][] D = new int[N][N];
+		for(int i=0;i<N;i++) for(int j=0;j<N;j++) {
+			if(V[i][j] != 0) D[i][j] = V[i][j];
+			else D[i][j] = INF;
+		}
+
+		for(int i=0;i<N;i++) for(int j=0;j<N;j++) for(int k=0;k<N;k++) if(D[j][k] > D[j][i] + D[i][k]) D[j][k] = D[j][i] + D[i][k];
+
+		return D[start][end];
+	}
+
+}
+
+```

권혁준_13주차/[BOJ-1561] 놀이 공원.md

@@ -0,0 +1,75 @@
+```java
+
+import java.util.*;
+import java.io.*;
+
+class Main {
+
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+
+	static long N;
+	static int M;
+	static int[] A;
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+
+	}
+
+	static void ready() throws Exception{
+
+		N = nextInt();
+		M = nextInt();
+		A = new int[M];
+		for(int i=0;i<M;i++) A[i] = nextInt();
+
+	}
+
+	static void solve() throws Exception{
+
+		long s = 0, e = (long)1e15, m = (s+e)>>1;
+		while(s<e) {
+			long cnt = M;
+			for(int i=0;i<M;i++) cnt += m/A[i];
+			if(cnt < N) s = m+1;
+			else e = m;
+			m = (s+e)>>1;
+		}
+
+		if(m == 0) {
+			bw.write(N + "\n");
+			return;
+		}
+		N -= M;
+		for(int i=0;i<M;i++) N -= (m-1)/A[i];
+		for(int i=0;i<M;i++) if(m % A[i] == 0) {
+			if(--N == 0) {
+				bw.write((i+1) + "\n");
+				return;
+			}
+		}
+
+	}
+
+}
+
+```

권혁준_13주차/[BOJ-16118] 달빛 여우.md

@@ -0,0 +1,111 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class Main {
+
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static String nextToken() throws Exception {
+		while(!st.hasMoreTokens()) nextLine();
+		return st.nextToken();
+	}
+	static int nextInt() throws Exception { return Integer.parseInt(nextToken()); }
+	static long nextLong() throws Exception { return Long.parseLong(nextToken()); }
+	static double nextDouble() throws Exception { return Double.parseDouble(nextToken()); }
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+
+	static int N, M;
+	static List<int[]>[] V;
+	static final int INF = (int)2e9;
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+
+	}
+
+	static void ready() throws Exception{
+
+		N = nextInt();
+		M = nextInt();
+		V = new List[N+1];
+		for(int i=1;i<=N;i++) V[i] = new ArrayList<>();
+		for(int i=0;i<M;i++){
+		    int a = nextInt(), b = nextInt(), c = nextInt();
+		    V[a].add(new int[]{b,c*2});
+		    V[b].add(new int[]{a,c*2});
+		}
+
+	}
+
+	static void solve() throws Exception{
+
+		int[] DA = new int[N+1];
+		Arrays.fill(DA, INF);
+		DA[1] = 0;
+		PriorityQueue<int[]> Q = new PriorityQueue<>((a,b) -> a[0]-b[0]);
+		Q.offer(new int[]{0,1});
+
+		while(!Q.isEmpty()){
+		    int[] now = Q.poll();
+		    int d = now[0], n = now[1];
+		    if(d > DA[n]) continue;
+		    for(int[] next:V[n]){
+		        int i = next[0], c = next[1];
+		        if(DA[i] > d+c){
+		            DA[i] = d+c;
+		            Q.offer(new int[]{DA[i],i});
+		        }
+		    }
+		}
+
+		int[][] DB = new int[N+1][2];
+		for(int i=1;i<=N;i++) Arrays.fill(DB[i], INF);
+		DB[1][0] = 0;
+		Q = new PriorityQueue<>((a,b) -> a[0]/2 + a[1]*2 - b[0]/2 - b[1]*2);
+		Q.offer(new int[]{0,0,1,0});
+		while(!Q.isEmpty()){
+		    int[] now = Q.poll();
+		    int a = now[0], b = now[1], n = now[2], k = now[3];
+		    if(a/2 + b*2 > DB[n][k]) continue;
+		    for(int[] next:V[n]){
+		        int i = next[0], c = next[1];
+		        int res = a/2 + b*2;
+		        if(k == 0){
+		            res += c/2;
+    		        if(DB[i][k^1] > res){
+    		            DB[i][k^1] = res;
+    		            Q.offer(new int[]{a+c,b,i,k^1});
+    		        }
+		        }
+		        else{
+		            res += c*2;
+		            if(DB[i][k^1] > res){
+		                DB[i][k^1] = res;
+		                Q.offer(new int[]{a,b+c,i,k^1});
+		            }
+		        }
+		    }
+		}
+
+		int ans = 0;
+		for(int i=2;i<=N;i++){
+		    int a = DA[i], b = Math.min(DB[i][0], DB[i][1]);
+		    if(a < b) ans++;
+		}
+		bw.write(ans + "\n");
+
+	}
+
+}
+```