import java.io.IOException; import java.io.InputStream; import java.util.Collections; import java.util.InputMismatchException; import java.util.LinkedList; public class roz { public static void main(String... args) { FastScanner scanner = new FastScanner(System.in); int numberOfStations = scanner.nextInt(); int numberOfForeignStations = scanner.nextInt(); StationNode[] stationsConnectedTo = new StationNode[numberOfStations + 1]; for (int i = 0; i < numberOfStations - 1; i++) { int stationA = scanner.nextInt(); int stationB = scanner.nextInt(); stationsConnectedTo[stationA] = new StationNode(stationB, stationsConnectedTo[stationA]); stationsConnectedTo[stationB] = new StationNode(stationA, stationsConnectedTo[stationB]); } StationNode queueFromRoot; { queueFromRoot = new StationNode(numberOfForeignStations + 1, null); boolean[] isScheduledForVisiting = new boolean[numberOfStations + 1]; isScheduledForVisiting[queueFromRoot.station] = true; StationNode visiting = queueFromRoot; while (visiting != null) { StationNode connection = stationsConnectedTo[visiting.station]; while (connection != null) { if (!isScheduledForVisiting[connection.station]) { isScheduledForVisiting[connection.station] = true; visiting.next = new StationNode(connection.station, visiting.next); } connection = connection.next; } visiting = visiting.next; } } StationNode queueFromLeafs = null; { StationNode visiting = queueFromRoot; while (visiting != null) { queueFromLeafs = new StationNode(visiting.station, queueFromLeafs); visiting = visiting.next; } } ArrowNode[] arrows = new ArrowNode[numberOfStations + 1]; { for (int station = 1; station <= numberOfForeignStations; station++) { int spacing = scanner.nextInt(); arrows[station] = new ArrowNode(spacing, true, new ArrowNode(spacing, false, null)); } } long totalPrice = 0; { boolean[] wasVisited = new boolean[numberOfStations + 1]; StationNode visiting = queueFromLeafs; while (visiting != null) { wasVisited[visiting.station] = true; StationNode connection = stationsConnectedTo[visiting.station]; while (true) { if (connection == null) { totalPrice += squash(arrows[visiting.station]); break; } if (!wasVisited[connection.station]) { totalPrice += squash(arrows[visiting.station]); arrows[visiting.station].next.next = arrows[connection.station]; arrows[connection.station] = arrows[visiting.station]; arrows[visiting.station] = null; break; } connection = connection.next; } visiting = visiting.next; } } System.out.println(totalPrice); } private static long squash(ArrowNode arrow) { long price = 0; LinkedList<ArrowNode> arrows = new LinkedList<ArrowNode>(); ArrowNode adding = arrow; while (adding != null) { arrows.add(adding); adding = adding.next; } Collections.sort(arrows); int left = -1; int right = -1; while (!arrows.isEmpty()) { if (!arrows.getFirst().isRight) { left = arrows.getFirst().spacing; arrows.removeFirst(); continue; } if (arrows.getLast().isRight) { right = arrows.getLast().spacing; arrows.removeLast(); continue; } left = arrows.getFirst().spacing; right = arrows.getLast().spacing; price += right - left; arrows.removeFirst(); arrows.removeLast(); } arrow.spacing = left; arrow.isRight = false; arrow.next = new ArrowNode(right, true, null); return price; } private static final class ArrowNode implements Comparable<ArrowNode> { int spacing; boolean isRight; ArrowNode next; public ArrowNode(int spacing, boolean isRight, ArrowNode next) { this.spacing = spacing; this.isRight = isRight; this.next = next; } public int compareTo(ArrowNode o) { return spacing - o.spacing; } } private static final class StationNode { int station; StationNode next; public StationNode(int station, StationNode next) { this.station = station; this.next = next; } } private static class FastScanner { private final InputStream stream; private final byte[] buf = new byte[1024]; private int curChar; private int numChars; private SpaceCharFilter filter; public FastScanner(InputStream stream) { this.stream = stream; } public int read() { if (numChars == -1) { throw new InputMismatchException(); } if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (numChars <= 0) { return -1; } } return buf[curChar++]; } public int nextInt() { int c = read(); while (isSpaceChar(c)) { c = read(); } int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if (c < '0' || c > '9') { throw new InputMismatchException(); } res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public boolean isSpaceChar(int c) { if (filter != null) { return filter.isSpaceChar(c); } return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 | import java.io.IOException; import java.io.InputStream; import java.util.Collections; import java.util.InputMismatchException; import java.util.LinkedList; public class roz { public static void main(String... args) { FastScanner scanner = new FastScanner(System.in); int numberOfStations = scanner.nextInt(); int numberOfForeignStations = scanner.nextInt(); StationNode[] stationsConnectedTo = new StationNode[numberOfStations + 1]; for (int i = 0; i < numberOfStations - 1; i++) { int stationA = scanner.nextInt(); int stationB = scanner.nextInt(); stationsConnectedTo[stationA] = new StationNode(stationB, stationsConnectedTo[stationA]); stationsConnectedTo[stationB] = new StationNode(stationA, stationsConnectedTo[stationB]); } StationNode queueFromRoot; { queueFromRoot = new StationNode(numberOfForeignStations + 1, null); boolean[] isScheduledForVisiting = new boolean[numberOfStations + 1]; isScheduledForVisiting[queueFromRoot.station] = true; StationNode visiting = queueFromRoot; while (visiting != null) { StationNode connection = stationsConnectedTo[visiting.station]; while (connection != null) { if (!isScheduledForVisiting[connection.station]) { isScheduledForVisiting[connection.station] = true; visiting.next = new StationNode(connection.station, visiting.next); } connection = connection.next; } visiting = visiting.next; } } StationNode queueFromLeafs = null; { StationNode visiting = queueFromRoot; while (visiting != null) { queueFromLeafs = new StationNode(visiting.station, queueFromLeafs); visiting = visiting.next; } } ArrowNode[] arrows = new ArrowNode[numberOfStations + 1]; { for (int station = 1; station <= numberOfForeignStations; station++) { int spacing = scanner.nextInt(); arrows[station] = new ArrowNode(spacing, true, new ArrowNode(spacing, false, null)); } } long totalPrice = 0; { boolean[] wasVisited = new boolean[numberOfStations + 1]; StationNode visiting = queueFromLeafs; while (visiting != null) { wasVisited[visiting.station] = true; StationNode connection = stationsConnectedTo[visiting.station]; while (true) { if (connection == null) { totalPrice += squash(arrows[visiting.station]); break; } if (!wasVisited[connection.station]) { totalPrice += squash(arrows[visiting.station]); arrows[visiting.station].next.next = arrows[connection.station]; arrows[connection.station] = arrows[visiting.station]; arrows[visiting.station] = null; break; } connection = connection.next; } visiting = visiting.next; } } System.out.println(totalPrice); } private static long squash(ArrowNode arrow) { long price = 0; LinkedList<ArrowNode> arrows = new LinkedList<ArrowNode>(); ArrowNode adding = arrow; while (adding != null) { arrows.add(adding); adding = adding.next; } Collections.sort(arrows); int left = -1; int right = -1; while (!arrows.isEmpty()) { if (!arrows.getFirst().isRight) { left = arrows.getFirst().spacing; arrows.removeFirst(); continue; } if (arrows.getLast().isRight) { right = arrows.getLast().spacing; arrows.removeLast(); continue; } left = arrows.getFirst().spacing; right = arrows.getLast().spacing; price += right - left; arrows.removeFirst(); arrows.removeLast(); } arrow.spacing = left; arrow.isRight = false; arrow.next = new ArrowNode(right, true, null); return price; } private static final class ArrowNode implements Comparable<ArrowNode> { int spacing; boolean isRight; ArrowNode next; public ArrowNode(int spacing, boolean isRight, ArrowNode next) { this.spacing = spacing; this.isRight = isRight; this.next = next; } public int compareTo(ArrowNode o) { return spacing - o.spacing; } } private static final class StationNode { int station; StationNode next; public StationNode(int station, StationNode next) { this.station = station; this.next = next; } } private static class FastScanner { private final InputStream stream; private final byte[] buf = new byte[1024]; private int curChar; private int numChars; private SpaceCharFilter filter; public FastScanner(InputStream stream) { this.stream = stream; } public int read() { if (numChars == -1) { throw new InputMismatchException(); } if (curChar >= numChars) { curChar = 0; try { numChars = stream.read(buf); } catch (IOException e) { throw new InputMismatchException(); } if (numChars <= 0) { return -1; } } return buf[curChar++]; } public int nextInt() { int c = read(); while (isSpaceChar(c)) { c = read(); } int sgn = 1; if (c == '-') { sgn = -1; c = read(); } int res = 0; do { if (c < '0' || c > '9') { throw new InputMismatchException(); } res *= 10; res += c - '0'; c = read(); } while (!isSpaceChar(c)); return res * sgn; } public boolean isSpaceChar(int c) { if (filter != null) { return filter.isSpaceChar(c); } return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1; } public interface SpaceCharFilter { public boolean isSpaceChar(int ch); } } } |