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package class38;
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// 360笔试题
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// 长城守卫军
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// 题目描述：
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// 长城上有连成一排的n个烽火台，每个烽火台都有士兵驻守。
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// 第i个烽火台驻守着ai个士兵，相邻峰火台的距离为1。另外，有m位将军，
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// 每位将军可以驻守一个峰火台，每个烽火台可以有多个将军驻守，
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// 将军可以影响所有距离他驻守的峰火台小于等于x的烽火台。
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// 每个烽火台的基础战斗力为士兵数，另外，每个能影响此烽火台的将军都能使这个烽火台的战斗力提升k。
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// 长城的战斗力为所有烽火台的战斗力的最小值。
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// 请问长城的最大战斗力可以是多少？
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// 输入描述
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// 第一行四个正整数n,m,x,k(1<=x<=n<=10^5,0<=m<=10^5,1<=k<=10^5)
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// 第二行n个整数ai(0<=ai<=10^5)
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// 输出描述 仅一行，一个整数，表示长城的最大战斗力
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// 样例输入
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// 5 2 1 2
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// 4 4 2 4 4
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// 样例输出
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// 6
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public class Code02_GreatWall {
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public static int maxForce(int[] wall, int m, int x, int k) {
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long L = 0;
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long R = 0;
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for (int num : wall) {
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R = Math.max(R, num);
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}
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R += m * k;
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long ans = 0;
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while (L <= R) {
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long M = (L + R) / 2;
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if (can(wall, m, x, k, M)) {
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ans = M;
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L = M + 1;
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} else {
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R = M - 1;
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}
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}
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return (int) ans;
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}
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public static boolean can(int[] wall, int m, int x, int k, long limit) {
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int N = wall.length;
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// 注意：下标从1开始
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SegmentTree st = new SegmentTree(wall);
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st.build(1, N, 1);
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int need = 0;
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for (int i = 0; i < N; i++) {
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// 注意：下标从1开始
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long cur = st.query(i + 1, i + 1, 1, N, 1);
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if (cur < limit) {
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int add = (int) ((limit - cur + k - 1) / k);
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need += add;
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if (need > m) {
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return false;
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}
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st.add(i + 1, Math.min(i + x, N), add * k, 1, N, 1);
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}
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}
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return true;
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}
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public static class SegmentTree {
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private int MAXN;
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private int[] arr;
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private int[] sum;
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private int[] lazy;
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private int[] change;
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private boolean[] update;
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public SegmentTree(int[] origin) {
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MAXN = origin.length + 1;
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arr = new int[MAXN];
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for (int i = 1; i < MAXN; i++) {
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arr[i] = origin[i - 1];
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}
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sum = new int[MAXN << 2];
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lazy = new int[MAXN << 2];
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change = new int[MAXN << 2];
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update = new boolean[MAXN << 2];
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}
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private void pushUp(int rt) {
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sum[rt] = sum[rt << 1] + sum[rt << 1 | 1];
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}
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private void pushDown(int rt, int ln, int rn) {
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if (update[rt]) {
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update[rt << 1] = true;
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update[rt << 1 | 1] = true;
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change[rt << 1] = change[rt];
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change[rt << 1 | 1] = change[rt];
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lazy[rt << 1] = 0;
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lazy[rt << 1 | 1] = 0;
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sum[rt << 1] = change[rt] * ln;
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sum[rt << 1 | 1] = change[rt] * rn;
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update[rt] = false;
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}
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if (lazy[rt] != 0) {
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lazy[rt << 1] += lazy[rt];
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sum[rt << 1] += lazy[rt] * ln;
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lazy[rt << 1 | 1] += lazy[rt];
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sum[rt << 1 | 1] += lazy[rt] * rn;
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lazy[rt] = 0;
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}
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}
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public void build(int l, int r, int rt) {
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if (l == r) {
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sum[rt] = arr[l];
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return;
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}
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int mid = (l + r) >> 1;
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build(l, mid, rt << 1);
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build(mid + 1, r, rt << 1 | 1);
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pushUp(rt);
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}
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public void update(int L, int R, int C, int l, int r, int rt) {
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if (L <= l && r <= R) {
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update[rt] = true;
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change[rt] = C;
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sum[rt] = C * (r - l + 1);
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lazy[rt] = 0;
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return;
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}
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int mid = (l + r) >> 1;
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pushDown(rt, mid - l + 1, r - mid);
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if (L <= mid) {
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update(L, R, C, l, mid, rt << 1);
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}
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if (R > mid) {
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update(L, R, C, mid + 1, r, rt << 1 | 1);
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}
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pushUp(rt);
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}
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public void add(int L, int R, int C, int l, int r, int rt) {
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if (L <= l && r <= R) {
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sum[rt] += C * (r - l + 1);
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lazy[rt] += C;
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return;
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}
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int mid = (l + r) >> 1;
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pushDown(rt, mid - l + 1, r - mid);
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if (L <= mid) {
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add(L, R, C, l, mid, rt << 1);
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}
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if (R > mid) {
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add(L, R, C, mid + 1, r, rt << 1 | 1);
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}
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pushUp(rt);
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}
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public long query(int L, int R, int l, int r, int rt) {
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if (L <= l && r <= R) {
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return sum[rt];
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}
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int mid = (l + r) >> 1;
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pushDown(rt, mid - l + 1, r - mid);
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long ans = 0;
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if (L <= mid) {
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ans += query(L, R, l, mid, rt << 1);
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}
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if (R > mid) {
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ans += query(L, R, mid + 1, r, rt << 1 | 1);
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}
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return ans;
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}
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}
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public static void main(String[] args) {
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int[] wall = { 3, 1, 1, 1, 3 };
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int m = 2;
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int x = 3;
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int k = 1;
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System.out.println(maxForce(wall, m, x, k));
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}
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}
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