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99 lines
2.5 KiB
99 lines
2.5 KiB
package class_2022_07_2_week;
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// 本题测试链接 : https://www.luogu.com.cn/problem/P5490
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// 提交以下代码，并把主类名改成"Main"
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// 可以直接通过
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import java.io.BufferedReader;
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import java.io.IOException;
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import java.io.InputStreamReader;
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import java.io.StreamTokenizer;
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import java.util.Arrays;
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public class Code05_LineSweepAlgorithm2 {
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public static int maxn = 300001;
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public static long[][] arr = new long[maxn][4];
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public static long[] orderedY = new long[maxn];
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public static long[] cover = new long[maxn << 2];
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public static long[] realLength = new long[maxn << 2];
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public static long[] left = new long[maxn << 2];
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public static long[] right = new long[maxn << 2];
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public static void main(String[] args) throws IOException {
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BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
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StreamTokenizer scanner = new StreamTokenizer(br);
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scanner.nextToken();
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int n = (int) scanner.nval;
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for (int i = 1; i <= n; i++) {
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scanner.nextToken();
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int x1 = (int) scanner.nval;
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scanner.nextToken();
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int y1 = (int) scanner.nval;
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scanner.nextToken();
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int x2 = (int) scanner.nval;
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scanner.nextToken();
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int y2 = (int) scanner.nval;
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orderedY[i] = y1;
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orderedY[i + n] = y2;
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arr[i][0] = x1;
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arr[i][1] = y1;
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arr[i][2] = y2;
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arr[i][3] = 1;
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arr[i + n][0] = x2;
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arr[i + n][1] = y1;
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arr[i + n][2] = y2;
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arr[i + n][3] = -1;
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}
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System.out.println(coverArea(n << 1));
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}
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public static long coverArea(int n) {
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Arrays.sort(orderedY, 1, n + 1);
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Arrays.sort(arr, 1, n + 1, (a, b) -> a[0] <= b[0] ? -1 : 1);
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build(1, n, 1);
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long preX = 0;
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long ans = 0;
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for (int i = 1; i <= n; i++) {
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ans += realLength[1] * (arr[i][0] - preX);
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preX = arr[i][0];
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add(arr[i][1], arr[i][2], (int) arr[i][3], 1);
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}
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return ans;
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}
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private static void build(int l, int r, int i) {
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if (r - l > 1) {
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int m = (l + r) >> 1;
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build(l, m, i << 1);
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build(m, r, (i << 1) | 1);
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}
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left[i] = orderedY[l];
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right[i] = orderedY[r];
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}
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private static void add(long L, long R, long C, int i) {
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long l = left[i];
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long r = right[i];
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if (L <= l && R >= r) {
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cover[i] += C;
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} else {
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if (L < right[i << 1]) {
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add(L, R, C, i << 1);
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}
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if (R > left[(i << 1) | 1]) {
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add(L, R, C, (i << 1) | 1);
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}
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}
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pushUp(i);
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}
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public static void pushUp(int i) {
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if (cover[i] > 0) {
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realLength[i] = right[i] - left[i];
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} else {
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realLength[i] = realLength[i << 1] + realLength[(i << 1) | 1];
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}
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}
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}
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