HDU 4941 Magical Forest(2014 Multi-University Training Contest 7)

思路：将行列离散化，那么就可以用vector 存下10W个点 ，对于交换操作 只需要将行列独立分开标记就行   。

r[i] 表示第 i 行存的是 原先的哪行         c[j] 表示 第 j 列 存的是原先的哪列。  

查询只需要一个二分即可。

#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<vector>
#define MAXN 100050
using namespace std;
int r[MAXN], c[MAXN];
struct info {
    int x, y, z;
} s[MAXN];
struct node {
    int va;
    int col;
};
bool operator<(node a, node b) {
    return a.col < b.col;
}
vector<node> e[MAXN];
int qr[MAXN];
int qc[MAXN];
int main() {
    int cntr, cntc, tt, ri = 0;
    scanf("%d", &tt);
    while (tt--) {
        int n, m, k, tailr, tailc;
        tailr = tailc = 0;
        scanf("%d%d%d", &n, &m, &k);
        for (int i = 0; i < k; ++i) {
            scanf("%d%d%d", &s[i].x, &s[i].y, &s[i].z);
            qr[tailr++] = s[i].x;
            qc[tailc++] = s[i].y;
        }
        sort(qr,qr+tailr);
        sort(qc,qc+tailc);
        tailr = unique(qr, qr + tailr) - qr;
        tailc = unique(qc, qc + tailc) - qc;
        for (int i = 0; i < tailr; ++i)
            e[i].clear();
        for (int i = 0; i < k; ++i) {
            int x = lower_bound(qr, qr + tailr, s[i].x) - qr;
            int y = lower_bound(qc, qc + tailc, s[i].y) - qc;
            node d;
            d.col = y;
            d.va = s[i].z;
            e[x].push_back(d);
        }
        for (int i = 0; i < tailr; ++i)
            sort(e[i].begin(), e[i].end());
        for (int i = 0; i < tailr; ++i)
            r[i] = i;
        for (int i = 0; i < tailc; ++i)
            c[i] = i;
        printf("Case #%d:
", ++ri);
        int T;
        scanf("%d", &T);
        while (T--) {
            int x, a, b;
            scanf("%d%d%d", &x, &a, &b);
            if (x == 1) {
                int idr = lower_bound(qr, qr + tailr, a) - qr;
                if (qr[idr] != a)
                    continue;
                int idc = lower_bound(qr, qr + tailr, b) - qr;
                if (qr[idc] != b)
                    continue;
                swap(r[idr], r[idc]);
            }
            if (x == 2) {
                int idr = lower_bound(qc, qc + tailc, a) - qc;
                if (qc[idr] != a)
                    continue;
                int idc = lower_bound(qc, qc + tailc, b) - qc;
                if (qc[idc] != b)
                    continue;
                swap(c[idr], c[idc]);
            }
            if (x == 3) {
                int idr = lower_bound(qr, qr + tailr, a) - qr;
                if (qr[idr] != a)
                {
                    puts("0");
                    continue;
                }
                int idc = lower_bound(qc, qc + tailc, b) - qc;
                if (qc[idc] != b)
                {
                    puts("0");
                    continue;
                }
                node cc;
                cc.col=c[idc];
                vector<node>::iterator it=lower_bound(e[r[idr]].begin(),e[r[idr]].end(),cc);
                if(it==e[r[idr]].end())
                {
                    puts("0");
                    continue;
                }
                node d=*(it);
                if(d.col!=c[idc])
                {
                    puts("0");
                    continue;
                }
                printf("%d
",d.va);
            }
        }
    }
    return 0;
}