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bzoj3671 [Noi2014]隨機數生成器

col cin lan return clu ... class www src

傳送門:http://www.lydsy.com/JudgeOnline/problem.php?id=3671

【題解】

貪心從1...n*m取,開兩個5000*5000的數組就夠了,可以重復利用,坐標可以壓到一個int裏。

每次暴力標記不能訪問的,標到已經有標記的就不用標了因為後面的肯定前面已經標記過了。

均攤復雜度就對了。復雜度$O(nm)$。

這破題還卡PE..

技術分享
# include <stdio.h>
# include <string.h>
# include <iostream>
# include <algorithm>
// # include <bits/stdc++.h>
using namespace std; typedef long long ll; typedef long double ld; typedef unsigned long long ull; const int M = 5e3 + 1; const int mod = 1e9+7; int mp[M][M]; int a[M * M], xc, A, B, C, D, n, m, T; inline int gnext(int x) { return (1ll * A * x % D * x % D + 1ll * B * x % D + C) % D; } # define id(i, j) (((i)
-1) * m + (j)) int main() { int Q; cin >> xc >> A >> B >> C >> D; cin >> n >> m >> Q; T = n*m; for (int i=1; i<=T; ++i) a[i] = i; for (int i=1; i<=T; ++i) { xc = gnext(xc); swap(a[i], a[xc % i + 1]); }
while(Q--) { scanf("%d%d", &A, &B); swap(a[A], a[B]); } for (int i=1; i<=n; ++i) for (int j=1; j<=m; ++j) mp[i][j] = a[id(i, j)]; for (int i=1; i<=n; ++i) for (int j=1; j<=m; ++j) a[mp[i][j]] = id(i, j), mp[i][j] = 0; int ux, uy, vx, vy, x, y, ok = 1; ux = n, uy = m, vx = 1, vy = 1; for (int i=1; i<=T; ++i) { x = (a[i] - 1) / m + 1; y = a[i] - (x-1) * m; if(!mp[x][y]) { if(ok) printf("%d", i), ok = 0; else printf(" %d", i); for (int a=x+1; a<=n; ++a) for (int b=y-1; b; --b) { if(mp[a][b]) break; mp[a][b] = 1; } for (int a=x-1; a; --a) for (int b=y+1; b<=m; ++b) { if(mp[a][b]) break; mp[a][b] = 1; } } } puts(""); return 0; }
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bzoj3671 [Noi2014]隨機數生成器