B. Collecting Packages

題目：B. Collecting Packages

簡單的搜索，爲啥當時沒做出來呢

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1005;

struct str{
    int x,y;
}a[N];
int n;

/*
1 2
1 3
3 3
4 3
5 5
*/
bool cmp(str a,str b){
    if(a.x == b.x) return a.y<b.y;
    return a.x<b.x;
}
void solve(){
    int x = 0,y = 0;   
    cin >> n;
    for(int i = 0;i < n;i++){
        scanf("%d%d",&a[i].x,&a[i].y);
    }
    sort(a,a+n,cmp);
    string s;
    int i = 0;
    while(i < n){
    //    cout<<x<<" "<<y<<endl;
    //    cout<<a[i].x<<" "<<a[i].y<<endl;
        if(x > a[i].x || y > a[i].y){
            cout<<"NO\n";
            return;
        }
        while(x < a[i].x){
            x++;
            s += "R";
        }
        while(y < a[i].y){
            y++;
            s += "U";
        }
        if(x == a[i].x && y == a[i].y){
            i++;
        }
    }
    cout<<"YES\n";
    cout<<s<<endl;
}
int main(){
    int t;
    cin >> t;
    while(t--)
    solve();
    return 0;
}