QMAX2 - Giá trị lớn nhất ver2

Tác giả: ladpro98

Ngôn ngữ: Java

import java.io.*;
import java.util.StringTokenizer;

public class Main {
    public static void main(String args[]) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        Solver object = new Solver();
        object.solve(in, out);
        out.close();
    }

    static class Solver {
        public void solve(InputReader in, PrintWriter out) {
            int n = in.nextInt();
            int m = in.nextInt();
            int a[] = new int[n + 1];
            SegmentTree T = new SegmentTree(a);
            for (int i = 1; i <= m; ++i) {
                int type = in.nextInt();
                int x = in.nextInt();
                int y = in.nextInt();
                if (type == 0) {
                    int value = in.nextInt();
                    T.increase(x, y, value);
                } else {
                    out.println(T.getMaxValue(x, y));
                }
            }
        }
    }

    static class SegmentTree {
        Node root;

        SegmentTree(int a[]) {
            root = build(a, 1, a.length - 1);
        }

        void increase(int i, int j, int value) {
            root.increase(i, j, value);
        }

        int getMaxValue(int i, int j) {
            return root.getMaxValue(i, j);
        }

        class Node {
            int l, r;
            int lazy;
            int maxValue;
            Node left, right;

            Node(int l, int r) {
                this.l = l;
                this.r = r;
                this.lazy = 0;
                this.maxValue = 0;
                this.left = null;
                this.right = null;
            }

            void gather() {
                maxValue = Math.max(left.maxValue, right.maxValue);
            }

            void pushDown() {
                if (lazy != 0) {
                    maxValue += lazy;
                    if (l != r) {
                        left.lazy += lazy;
                        right.lazy += lazy;
                    }
                    lazy = 0;
                }
            }

            int getMaxValue(int i, int j) {
                pushDown();
                if (r < i || j < l) return 0;
                if (i <= l && r <= j) return maxValue;
                return Math.max(left.getMaxValue(i, j), right.getMaxValue(i, j));
            }

            void increase(int i, int j, int value) {
                pushDown();
                if (r < i || j < l) return;
                if (i <= l && r <= j) {
                    lazy += value;
                    pushDown();
                    return;
                }
                left.increase(i, j, value);
                right.increase(i, j, value);
                gather();
            }
        }

        Node build(int a[], int l, int r) {
            Node cur = new Node(l, r);
            if (l == r) {
                cur.maxValue = a[l];
                return cur;
            }
            int mid = l + r >> 1;
            cur.left = build(a, l, mid);
            cur.right = build(a, mid + 1, r);
            cur.gather();
            return cur;
        }
    }

    static class InputReader {
        public BufferedReader reader;
        public StringTokenizer tokenizer;

        public InputReader(InputStream stream) {
            reader = new BufferedReader(new InputStreamReader(stream), 32768);
            tokenizer = null;
        }

        public String next() {
            while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

    }
}

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