2019 HDU 多校第9场 1002.Rikka with Cake（树状数组+离散化）

#include<bits/stdc++.h>

using namespace std;

#define maxn 100005
#define ll long long
#define ls l,mid,rt<<1
#define rs mid+1,r,rt<<1|1
typedef pair<int,int> PII;
const int mod = 1e9+7;

int sum[maxn],N;
struct Point{
    int x,y;
    char D;
}points[maxn];

bool cmp(Point A,Point B){
    return A.y<B.y;
}

bool cmp1(Point A,Point B){
    return A.x<B.x;
}

inline int lowbits(int x){
    return x&-x;
}

void update(int x,int p){
    for(;x<N;x+=lowbits(x))sum[x]+=p;
}

int getsum(int x){
    int ans = 0;
    for(;x>0;x-=lowbits(x))ans+=sum[x];
    return ans;
}

int main(){
    int T;cin>>T;
    while(T--){
        int n,m,k;
        scanf("%d %d %d",&n,&m,&k);
        for(int i=0;i<k;i++){
            int x,y;char D;
            scanf("%d %d %c",&x,&y,&D);
            getchar();
            points[i]=Point{x,y,D};
        }
        sort(points,points+k,cmp);
        for(int i=0;i<k;i++)points[i].y=i+1;
        sort(points,points+k,cmp1);
        for(int i=0;i<=k;i++)sum[i]=0;
        ll ans=0;
        for(int i=0;i<k;i++){
            if(points[i].D=='U')update(points[i].y+1,1);
            else if(points[i].D=='D'){
                update(1,1);
                update(points[i].y,-1);
            }
            else if(points[i].D=='L')
                ans+=(ll)(getsum(points[i].y));
        }
        N=k+10;
        for(int i=0;i<=N;i++)sum[i]=0;
        for(int i=k-1;i>=0;i--){
            if(points[i].D=='U')update(points[i].y+1,1);
            else if(points[i].D=='D'){
                update(1,1);
                update(points[i].y,-1);
            }
            else if(points[i].D=='R')
                ans+=(ll)(getsum(points[i].y));
        }
        printf("%lld
",ans+1);
    }
    return 0;
}