vVYlLm - Online C++0x Compiler & Debugging Tool

#include <bits/stdc++.h>
using namespace std;
#define int              long long int
#define double           long double
#define print(a)         for(auto x : a) cout << x << " "; cout << endl
inline int power(int a, int b) {
    int x = 1;
    while (b) {
        if (b & 1) x *= a;
        a *= a;
        b >>= 1;
    }
    return x;
}


const int M = 1000000007;
const int N = 3e5+9;
const int INF = 2e9+1;
const int LINF = 2000000000000000001;

//_ ***************************** START Below *******************************


bool isPossible(int n, int m, int k, int mid){

	int sum = (mid*(mid+1)/2) * 2;


	int left = mid - k;
	if(left<0){
		sum += abs(left);
		left = 0;
	}

	int right = mid - (n-k) - 1;
	if(right<0){
		sum += abs(right);
		right = 0;
	}

	sum -= (left*(left+1)/2 + right*(right+1)/2 + mid);

	return sum<=m;

}

void consistency(int n, int m, int k){

	int s = 1, e = INF;

	while(s<e){
		int mid = s + (e-s+1)/2;
		if(isPossible(n, m, k, mid)){
			s = mid;
		}
		else e = mid-1;;
	}

	cout << e << endl;

}

void solve() {

    int n, m, k;
    cin>>n >> m >> k;

    consistency(n, m, k);


}


int32_t main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    int t = 1;
    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}