백준 1004번 : 어린왕자 - C++

https://www.acmicpc.net/problem/1004

1004번: 어린 왕자

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

int stx,sty, enx,eny;

bool inAndOut(int x, int y, int r){
    int startToCircleDist = (stx-x)*(stx-x) + (sty-y)*(sty-y);
    int endToCircleDist = (enx-x)*(enx-x) + (eny-y)*(eny-y);
    int R = r*r;

    if((startToCircleDist > R && endToCircleDist < R)||(startToCircleDist < R && endToCircleDist > R)) return true;
    return false;
}


int main() {
    ios::sync_with_stdio(0); cin.tie(0);

    int T;
    cin>> T;
    for(int t=0;t<T; t++){
        int n;
        cin >> stx >> sty >> enx >> eny >> n;

        int ans = 0;
        for(int i=0; i<n; i++){
            int x, y, r;
            cin >> x >> y >> r;
            if(inAndOut(x,y,r)) ans++;
        }
        cout << ans << '\n';
    }

    return 0;
}