05 최단 경로

05_shortest_path/kim/13549.java

@@ -0,0 +1,61 @@
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static class Node {
+        int time;
+        int now;
+
+        Node(int time, int now) {
+            this.time = time;
+            this.now = now;
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken());
+        int K = Integer.parseInt(st.nextToken());
+
+        if (N >= K) {
+            System.out.println(N - K);
+            return;
+        }
+
+        int[] go = new int[140_001];
+        for (int i = 0; i < go.length; i++) {
+            go[i] = Integer.MAX_VALUE;
+        }
+
+        PriorityQueue<Node> queue = new PriorityQueue<>((s, e) -> Integer.compare(s.time, e.time));
+        queue.add(new Node(0, N));
+
+        while (!queue.isEmpty()) {
+            Node now = queue.poll();
+            int nnode = now.now;
+            if (nnode == K) {
+                System.out.println(now.time);
+                return;
+            }
+
+            int[] move = { nnode + 1, nnode - 1 };
+            for (int next : move) {
+                if (next < 0 || next > 140_000) continue;
+                if (go[next] > now.time + 1 && now.time + 1 <= (K-N)) {
+                    queue.add(new Node(now.time + 1, next));
+                    go[next] = now.time + 1;
+                }
+            }
+
+            if (nnode * 2 <= 0 || nnode * 2 > 140_000) continue;
+            else {
+                if (go[nnode * 2] > now.time && now.time <= (K-N)) {
+                    queue.add(new Node(now.time, nnode * 2));
+                    go[nnode * 2] = now.time;
+                }
+            }
+        }
+    }
+}

05_shortest_path/kim/1446.java

@@ -0,0 +1,56 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+    static class Node{
+        int s;
+        int e;
+        int w;
+        Node(int s, int e, int w) {
+            this.s = s;
+            this.e = e;
+            this.w = w;
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int D = Integer.parseInt(st.nextToken());
+
+        int[] dp = new int[10_001];
+        Arrays.fill(dp, Integer.MAX_VALUE);
+        dp[0] = 0;
+
+        Set<Integer> set = new HashSet<>();
+        List<Node> list = new ArrayList<>();
+
+        for(int n = 0; n < N; n++) {
+            st = new StringTokenizer(br.readLine());
+
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+            int w = Integer.parseInt(st.nextToken());
+
+            if (e > D) continue;
+
+            list.add(new Node(s, e, w));
+
+            set.add(s);
+            set.add(e);
+        }
+
+        for(int i = 0; i < 10_000; i++) {
+            dp[i + 1] = Math.min(dp[i+1], dp[i] + 1);
+
+            for(Node now : list) {
+                if(now.s == i)
+                    dp[now.e] = Math.min(dp[i] + now.w, dp[now.e]);
+            }
+        }
+
+        System.out.println(dp[D]);
+    }
+}

05_shortest_path/kim/14938.java

@@ -0,0 +1,68 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+        int R = Integer.parseInt(st.nextToken());
+
+        int[] items = new int[N];
+        boolean[] visited = new boolean[N];
+        int[][] map = new int[N+1][N+1];
+
+        // 아이템 초기화
+        st = new StringTokenizer(br.readLine());
+        for(int n = 0; n < N; n++)
+            items[n] = Integer.parseInt(st.nextToken());
+
+        // 맵 초기화
+        for(int i = 1; i <= N; i++) {
+            for(int j = 1; j <= N; j++) {
+                if(i == j) continue;
+                map[i][j] = Integer.MAX_VALUE;
+            }
+        }
+
+        for(int r = 0; r < R; r++) {
+            st = new StringTokenizer(br.readLine());
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+            int w = Integer.parseInt(st.nextToken());
+            if (w > M) continue;
+            map[s][e] = w;
+            map[e][s] = w;
+        }
+
+        for(int m = 1; m <= N; m++) {
+            for(int s = 1; s <= N; s++) {
+                for(int e =1; e <= N; e++) {
+                    if (map[s][m] == Integer.MAX_VALUE || map[m][e] == Integer.MAX_VALUE) continue;
+                    if (map[s][m] + map[m][e] > M) continue;
+
+                    map[s][e] = Math.min(map[s][e], map[s][m] + map[m][e]);
+                }
+            }
+        }
+
+        int max = 0;
+        for(int i = 1; i <= N; i++) {
+            int buf = 0;
+            Set<Integer> set = new HashSet<>();
+
+            for(int j = 1; j <= N; j++) {
+                if (map[i][j] != Integer.MAX_VALUE) set.add(j);
+            }
+            for(int s : set) buf += items[s-1];
+            max = Math.max(max, buf);
+        }
+
+        System.out.println(max);
+    }
+}

05_shortest_path/kim/1719.java

@@ -0,0 +1,85 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+    static int N;
+    static HashMap<Integer, List<Node>> routes;
+    static StringBuilder sb = new StringBuilder();
+
+    static class Node {
+        int node;
+        int dist;
+        int route;
+
+        Node(int node, int dist, int route) {
+            this.node = node;
+            this.dist = dist;
+            this.route = route;
+        }
+
+        @Override
+        public String toString() {
+            return "{node} " + this.node + " " + this.dist + " " + this.route;
+        }
+    }
+
+    public static void dijkstra(int startNode) {
+        PriorityQueue<Node> queue = new PriorityQueue<>((s, e) -> s.dist- e.dist);
+
+        int[] path = new int[N+1];
+        path[startNode] = startNode;
+        for(Node n : routes.getOrDefault(startNode, new ArrayList<>())) {
+            queue.add(new Node(n.node, n.dist, n.route));
+        }
+
+        while (!queue.isEmpty()) {
+            Node now = queue.poll();
+            if (path[now.node] != 0) continue;
+            path[now.node] = now.route;
+            for(Node n : routes.getOrDefault(now.node, new ArrayList<>())) {
+                if (path[n.node] == 0) {
+                    queue.add(new Node(n.node, now.dist + n.dist, now.route));
+                }
+            }
+        }
+
+        for(int i = 1; i <= N; i++) {
+            if (i == startNode) sb.append("- ");
+            else sb.append(path[i]).append(" ");
+        }
+        sb.append("\n");
+
+    }
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+
+        routes = new HashMap<>();
+
+        for(int m = 0; m < M; m++) {
+            st = new StringTokenizer(br.readLine());
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+            int w = Integer.parseInt(st.nextToken());
+
+            if (!routes.containsKey(s))
+                routes.put(s, new ArrayList<>());
+            if (!routes.containsKey(e))
+                routes.put(e, new ArrayList<>());
+
+            routes.get(s).add(new Node(e, w, e));
+            routes.get(e).add(new Node(s, w, s));
+        }
+
+        for(int i = 1; i <= N; i++) {
+            dijkstra(i);
+        }
+
+        System.out.println(sb);
+    }
+}

05_shortest_path/kim/18352.java

@@ -0,0 +1,56 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+    public static void main(String[] args) throws Exception {
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        int N = Integer.parseInt(st.nextToken()); // 도시 개수
+        int M = Integer.parseInt(st.nextToken()); // 도로 개수
+        int K = Integer.parseInt(st.nextToken()); // 거리 정보
+        int X = Integer.parseInt(st.nextToken()); // 출발 도시
+
+        Map<Integer, List<Integer>> roads = new HashMap<>();
+
+        for(int i = 0; i < M; i++) {
+            st = new StringTokenizer(br.readLine());
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+
+            List<Integer> buf = roads.getOrDefault(s, new ArrayList<>());
+            buf.add(e);
+            roads.put(s, buf);
+        }
+
+        int[] minDist = new int[N+1];
+        boolean[] visited = new boolean[N+1];
+
+        Queue<Integer> queue = new LinkedList<>();
+        queue.add(X);
+        visited[X] = true;
+        while(!queue.isEmpty()) {
+            int now = queue.poll();
+            for(int next : roads.getOrDefault(now, new ArrayList<>())) {
+                if (!visited[next]) {
+                    minDist[next] = minDist[now] + 1;
+                    queue.add(next);
+                    visited[next] = true;
+                }
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+        boolean isAns = false;
+        for(int i = 1; i <= N; i++) {
+            if(minDist[i] == K) {
+                sb.append(i).append("\n");
+                isAns = true;
+            }
+        }
+
+        System.out.println(isAns ? sb : -1);
+    }
+}

05_shortest_path/kim/4485.java

@@ -0,0 +1,58 @@
+import java.io.*;
+import java.util.*;
+
+
+public class Main {
+
+    static int[][] move = {{1,0}, {0,1}, {-1, 0}, {0, -1}};
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringBuilder sb = new StringBuilder();
+
+        int test = 1;
+
+        while(true) {
+            int N = Integer.parseInt(br.readLine());
+            if (N == 0) break;
+
+            int[][] map = new int[N][N];
+            int[][] result = new int[N][N];
+            boolean[][] visited = new boolean[N][N];
+
+            for(int i = 0; i < N; i++) {
+                StringTokenizer st = new StringTokenizer(br.readLine());
+                for(int j = 0; j <N; j++) {
+                    int num = Integer.parseInt(st.nextToken());
+                    map[i][j] = num;
+                    result[i][j] = num;
+                }
+            }
+
+            Queue<int[]> queue = new LinkedList<>();
+            queue.add(new int[] {0, 0});
+            visited[0][0] = true;
+            result[0][0] = map[0][0];
+
+            while(!queue.isEmpty()) {
+                int[] now = queue.poll();
+
+                for(int[] mv : move) {
+                    int nextn = now[0] + mv[0];
+                    int nextm = now[1] + mv[1];
+
+                    if(nextn < 0 || nextm < 0 || nextn >= N || nextm >= N) continue;
+                    if(visited[nextn][nextm] && result[nextn][nextm] <= result[now[0]][now[1]] + map[nextn][nextm]) continue;
+
+                    result[nextn][nextm] = result[now[0]][now[1]] + map[nextn][nextm];
+                    visited[nextn][nextm] = true;
+                    queue.add(new int[] {nextn, nextm});
+                }
+            }
+
+            sb.append("Problem ").append(test++).append(": ").append(result[N-1][N-1]).append("\n");
+        }
+
+        System.out.println(sb);
+    }
+}