USACO Shaping Regions(离散化)

　　记录一下我一直很怕做的一道离散化题。都卡了大半个月了，今天终于过了。这种离散化的题就一个恶心，不然早就啃过去了。

代码如下：

/*
ID: lyon.ly1
LANG: C++
TASK: rect1
*/

#include <cstring>
#include <iomanip>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <ctime>
#include <map>
#include <set>

using namespace std;

#define PB push_back
#define FI first
#define SE second
#define MPR make_pair
#define REP(i, n) for (int i = 0; i < n; i++)
#define REP_1(i, n) for (int i = 1; i <= n; i++)
#define FORI(i, a, b) for (int i = a; i < b; i++)
#define FORD(i, a, b) for (int i = a; i > b; i--)
#define _clr(x) memset(x, 0, sizeof(x))
#define _rst(x) memset(x, -1, sizeof(x))

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<LL> VLL;
typedef vector<PII> VPII;
typedef vector<int> VI;
typedef vector<double> VDBL;
const int N = 2505;
const int hashMod = 1e6 + 5;
const int inf = 0x55555555;
const double eps = 1e-8;
const LL linf = 0x5555555555555555ll;
const double finf = 1e50;
const double pi = acos(-1.0);
const int mod = 1e9 + 7;

FILE *fin = fopen("rect1.in", "r");
FILE *fout = fopen("rect1.out", "w");

struct Rect {
    int x1, y1, x2, y2, cl;
    Rect(int a = 0, int b = 0, int c = 0, int d = 0, int e = 0) {
        if (a > c) swap(a, c);
        if (b > d) swap(b, d);
        x1 = a, y1 = b, x2 = c, y2 = d, cl = e;
    }
} ;

queue<Rect> Q;
int clr[N];

bool belong(int x1, int y1, int x2, int y2, Rect &x) {
    return x.x1 <= x1 && x2 <= x.x2 && x.y1 <= y1 && y2 <= x.y2;
}

void insert(Rect x) {
    int sz = Q.size();
    int X[5], Y[5];
    while (sz--) {
        Rect tmp = Q.front();
//        printf("!!!          %d %d %d %d %d\n", tmp.x1, tmp.y1, tmp.x2, tmp.y2, tmp.cl);
        Q.pop();
        if (tmp.x2 <= x.x1 || x.x2 <= tmp.x1) { Q.push(tmp); continue;}
        if (tmp.y2 <= x.y1 || x.y2 <= tmp.y1) { Q.push(tmp); continue;}
//        puts("~~~~~~~~~~~~~~~");
//        printf("rect %d %d %d %d %d\n", tmp.x1, tmp.y1, tmp.x2, tmp.y2, tmp.cl);
        X[0] = x.x1, X[1] = x.x2;
        Y[0] = x.y1, Y[1] = x.y2;
        X[2] = tmp.x1, X[3] = tmp.x2;
        Y[2] = tmp.y1, Y[3] = tmp.y2;
        sort(X, X + 4);
        sort(Y, Y + 4);
//        REP(i, 4) {
//            printf("x %d y %d\n", X[i], Y[i]);
//        }
        REP(i, 3) {
            if (X[i] == X[i + 1]) continue;
            REP(j, 3) {
                if (Y[j] == Y[j + 1]) continue;
                if (belong(X[i], Y[j], X[i + 1], Y[j + 1], tmp) && !belong(X[i], Y[j], X[i + 1], Y[j + 1], x)) {
                    Q.push(Rect(X[i], Y[j], X[i + 1], Y[j + 1], tmp.cl));
//                    printf("pb %d %d %d %d %d\n", X[i], Y[j], X[i + 1], Y[j + 1], tmp.cl);
                }
            }
        }
//        puts("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
    }
    Q.push(x);
}

int main() {
    int a, b, c, d, e, n;
//    freopen("in", "r", stdin);
    while (~fscanf(fin, "%d%d%d", &a, &b, &n)) {
        while (Q.size()) Q.pop();
        _clr(clr);
        Q.push(Rect(0, 0, a, b, 1));
        while (n--) {
            fscanf(fin, "%d%d%d%d%d", &a, &b, &c, &d, &e);
//            printf("Rect ~~~~~~~~~~~~~~~~~~     %d %d %d %d %d\n", a, b, c, d, e);
            insert(Rect(a, b, c, d, e));
        }
        while (Q.size()) {
            Rect tmp = Q.front();
//            printf("%d %d %d %d %d\n", tmp.x1, tmp.y1, tmp.x2, tmp.y2, tmp.cl);
            Q.pop();
            clr[tmp.cl] += (tmp.x2 - tmp.x1) * (tmp.y2 - tmp.y1);
        }
        REP(i, N) {
            if (clr[i]) {
                fprintf(fout, "%d %d\n", i, clr[i]);
            }
        }
    }
    return 0;
}

——written by Lyon