Submission #136217

#	Time	Username	Problem	Language	Result	Execution time	Memory
136217		arnold518	허수아비 (JOI14_scarecrows)	C++14	100 / 100	660 ms	67412 KiB

scarecrows

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 2e5;

struct Point
{
    int x, y;
    Point() : x(0), y(0) {}
    Point(int x, int y) : x(x), y(y) {}
};

int N;
Point point[MAXN+10];
ll ans;

vector<Point> tree[MAXN*4+10];

void update(int node, int tl, int tr, int pos, Point p)
{
    if(pos<tl || tr<pos) return;
    if(tl==tr)
    {
        tree[node].push_back(p);
        return;
    }
    int mid=tl+tr>>1;
    update(node*2, tl, mid, pos, p);
    update(node*2+1, mid+1, tr, pos, p);

    while(!tree[node].empty() && tree[node].back().y<p.y) tree[node].pop_back();
    tree[node].push_back(p);
}

int ret, pos;
void query(int node, int tl, int tr, int l, int r)
{
    if(r<tl || tr<l) return;
    if(l<=tl && tr<=r)
    {
        if(tree[node].empty()) return;
        ret+=tree[node].end()-lower_bound(tree[node].begin(), tree[node].end(), Point(pos, 0), [&](const Point& p, const Point& q) { return p.x<q.x; });
        pos=max(pos, tree[node].back().x);
        return;
    }
    int mid=tl+tr>>1;
    query(node*2+1, mid+1, tr, l, r);
    query(node*2, tl, mid, l, r);
}

int main()
{
    int i, j;

    scanf("%d", &N);
    for(i=1; i<=N; i++) scanf("%d%d", &point[i].x, &point[i].y);

    sort(point+1, point+N+1, [&](const Point& p, const Point& q) { return p.y<q.y; });
    for(i=1; i<=N; i++) point[i].y=i;

    sort(point+1, point+N+1, [&](const Point& p, const Point& q) { return p.x<q.x; });
    for(i=1; i<=N; i++) point[i].x=i;

    for(i=1; i<=N; i++)
    {
        ret=0, pos=-1;
        query(1, 1, N, 1, point[i].y);
        ans+=ret;
        update(1, 1, N, point[i].y, point[i]);
    }
    printf("%lld", ans);
}

Compilation message (stderr)

scarecrows.cpp: In function 'void update(int, int, int, int, Point)':
scarecrows.cpp:31:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid=tl+tr>>1;
             ~~^~~
scarecrows.cpp: In function 'void query(int, int, int, int, int)':
scarecrows.cpp:50:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid=tl+tr>>1;
             ~~^~~
scarecrows.cpp: In function 'int main()':
scarecrows.cpp:57:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
scarecrows.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
     ~~~~~^~~~~~~~~~
scarecrows.cpp:60:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(i=1; i<=N; i++) scanf("%d%d", &point[i].x, &point[i].y);
                         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 85 / 85