'commit'

TangDou/AcWing/ErFenTu/POJ1548_LSH.cpp

@@ -0,0 +1,87 @@
+#include <iostream>
+#include <cstdio>
+#include <cstring>
+#include <vector>
+#include <set>
+#include <algorithm>
+using namespace std;
+
+typedef pair<int, int> PII;
+#define x first
+#define y second
+
+const int N = 1010, M = N * N;
+
+int e[M], h[N], idx, w[M], ne[M];
+void add(int a, int b, int c = 0) {
+    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
+}
+
+int st[N], match[N];
+int dfs(int u) {
+    for (int i = h[u]; ~i; i = ne[i]) {
+        int v = e[i];
+        if (st[v] == 1) continue;
+        st[v] = 1;
+        if (match[v] == -1 || dfs(match[v])) {
+            match[v] = u;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+int main() {
+#ifndef ONLINE_JUDGE
+    freopen("POJ1548.in", "r", stdin);
+#endif
+    int a, b;
+    while (true) {
+        memset(match, -1, sizeof match);
+        memset(st, 0, sizeof st);
+
+        memset(h, -1, sizeof h);
+        idx = 0;
+
+        vector<PII> vec;
+        while (true) {
+            cin >> a >> b;
+            if (a == 0 && b == 0) break;
+            if (a == -1 && b == -1) exit(0);
+            vec.push_back(make_pair(a, b));
+        }
+
+        sort(vec.begin(), vec.end());
+
+        vector<int> alls; // 存储所有待离散化的值
+        for (int i = 0; i < vec.size(); i++)
+            for (int j = i + 1; j < vec.size(); j++)
+                if (vec[j].y >= vec[i].y) alls.push_back(i), alls.push_back(j);
+
+        // 将所有值排序
+        sort(alls.begin(), alls.end());
+        // 去掉重复元素
+        alls.erase(unique(alls.begin(), alls.end()), alls.end());
+
+        // 重新捋着建边，通过二分查找，找出新的序号，这样就可以使用i<=alls.size()了！
+        for (int i = 0; i < vec.size(); i++)
+            for (int j = i + 1; j < vec.size(); j++)
+                if (vec[j].y >= vec[i].y) {
+                    int x = lower_bound(alls.begin(), alls.end(), i) - alls.begin();
+                    int y = lower_bound(alls.begin(), alls.end(), j) - alls.begin();
+                    add(x, y);
+                }
+
+        int res = 0;
+
+        for (int i = 0; i < alls.size(); i++) {
+            // 最开始黄海SB的以为二分后，这里可以使用i<idx做为终止条件，其实是SB到家了！idx是边数，是边数，是边数！
+            // 不是点数，不是点数，不是点数！
+            memset(st, 0, sizeof st);
+            if (dfs(i)) res++;
+        }
+
+        printf("%d\n", vec.size() - res);
+    }
+    return 0;
+}