poj 1836 Alignment

一下午赶作业很郁闷啊！头晕死了，出来做个水题放松一下……

两边分别找最长上升子序列，然后再扫一遍就可以了。

/*
* Author: stormdpzh
* POJ: 1836 Alignment
* Time: 2012/4/30 16:12:47
*/
#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <vector>
#include <queue>
#include <stack>
#include <set>
#include <algorithm>
#include <functional>

#define sz(v) ((int)(v).size())
#define rep(i, n) for(int i = 0; i < n; i++)
#define repf(i, a, b) for(int i = a; i <= b; i++)
#define out(n) printf("%d\n", n)
#define wh(n) while(scanf("%d", &n) != EOF)
#define whz(n) while(scanf("%d", &n) != EOF && n != 0)
#define int64 long long

using namespace std;

int n;
double height[1005];
int rec[2][1005]; //rec[0][i], left 2 right, rec[1][i], right 2 left

int solve()
{
memset(rec, 0, sizeof(rec));

rec[0][0] = 1;
repf(i, 1, n - 1) {
rep(j, i) {
if(height[i] > height[j])
rec[0][i] = max(rec[0][j] + 1, rec[0][i]);
}
if(rec[0][i] == 0)
rec[0][i]++;
}

rec[1][n - 1] = 1;
for(int i = n - 2; i >= 0; i--) {
int tmp = 0;
repf(j, i + 1, n - 1) {
if(height[i] > height[j])
rec[1][i] = max(rec[1][j] + 1, rec[1][i]);
}
if(rec[1][i] == 0)
rec[1][i]++;
}

int ans = 0;
rep(i, n) {
int tmp = 0;
repf(j, i + 1, n - 1) {
if(height[i] >= height[j]) {
tmp = max(tmp, rec[1][j]);
}
}
ans = max(ans, tmp + rec[0][i]);
}
return ans;
}

int main()
{
//freopen("data.in", "r", stdin);
wh(n) {
rep(i, n)
scanf("%lf", &height[i]);
out(n - solve());
}

return 0;
}