[BZOJ3671][Noi2014]隨機數生成器 && 貪心

被模擬退火虐了一晚上 搞道貪心壓壓驚？

開始看到題目下面一大段說明不明來意 後來發現喪心病狂的卡內存也是有意思.....

不難看出含有最小的一個數的路徑一定比不含的優 然後開始貪心

每選擇一個數 維護其他所有行可以取的區間

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#include<queue>
#include<set>
#define SF scanf
#define PF printf
using namespace std;
typedef long long LL;
const int MAXN = 5000;
LL a, b, c, d, S;
int n, m, Q;
int A[MAXN*MAXN+10], M[MAXN+10][MAXN+10], up[MAXN+10], down[MAXN+10];
int ans[MAXN*2+10];
inline int GetNum() {
	return S = (S*S*a % d + S*b % d + c) % d;
}
void del(int x, int y) {
	for(int i = 1; i < x; i++) up[i] = min(up[i], y);
	for(int i = x+1; i <= n; i++) down[i] = max(down[i], y);
}
int main() {
	cin >> S >> a >> b >> c >> d;
	SF("%d%d%d", &n, &m, &Q);
	for(int i = 1; i <= n; i++) up[i] = m;
	for(int i = 1; i <= n*m; i++) {
		A[i] = i; swap(A[i], A[GetNum()%i+1]);
	}
	for(int i = 1; i <= Q; i++) {
		int x, y; SF("%d%d", &x, &y);
		swap(A[x], A[y]);
	}
	int cur = 0;
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++)
			M[i][j] = A[++cur];
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++)
			A[M[i][j]] = (i-1)*m+j;
	bool first = false;
	for(int i = 1; i <= n*m; i++) {
		int y = A[i] % m, x = A[i] / m + 1;
		if(A[i] % m == 0) {
			x--; y = m;
		}
		if(down[x] <= y && y <= up[x]) {
			del(x, y);
			if(first) putchar(' ');
			first = true;
			PF("%d", M[x][y]);
		}
	}
}