Aizu 0033 Ball(dfs,贪心)

日文题面...题意：是把一连串的有编号的球往左或者往右边放。问能不能两边都升序。

记录左边和右边最上面的球编号大小，没有就-1，dfs往能放的上面放。

#include<bits/stdc++.h>
using namespace std;

inline int read()
{
    int ret; char c; while(c = getchar(),c<''||c>'');
    ret = c-'';
    while(c = getchar(),c>=''&&c<='') ret = ret* + c-'';
    return ret;
}

int reads()
{
    int ret; char c; while(c = getchar(),c != '-' && c<''||c>'');
    bool Sign = c == '-';
    ret = Sign?:c-'';
    while(c = getchar(),c>=''&&c<='') ret = ret* + c-'';
    return Sign?-ret:ret;
}

int a[];

bool dfs(int i = ,int lsl = -,int lsr = -)
{
    if(i == ) return true;
    return ( (!~lsl || a[i] > a[lsl]) && dfs(i+,i,lsr) )||( (!~lsr || a[i] > a[lsr]) && dfs(i+,lsl,i) );
}

//#define LOCAL
int main()
{
#ifdef LOCAL
    freopen("in.txt","r",stdin);
#endif
    int T = read();
    while(T--){
        for(int i = ; i < ; i++) a[i] = read();
        puts(dfs()?"YES":"NO");
    }
    return ;
}