1163A - Eating Soup - CodeForces Solution

#include "bits/stdc++.h"

using namespace std;

#define mod 1000000007
#define MOD1 998244353
#define rep(i,b)  for(int i = 0; i < b; i++)
#define nl "\n"
#define sp " "
#define inf 1e9 + 4
#define pb push_back
#define vi vector<int>
#define all(x) (x).begin(), (x).end()
#define ys cout << "YES" << nl
#define no cout << "NO" << nl
#define pi 3.141592653589793238462
#define ll long long
// #define int long long
template<typename T> istream& operator>>(istream& is,  vector<T> &v){for (auto& i : v) is >> i;        return is;}
template<typename T> ostream& operator<<(ostream& os,  vector<T>  v){for (auto& i : v) os << i << ' '; return os;}
vector<ll> sieve(int n) {int*v = new int[n + 1](); vector<ll> vect; for (int i = 2; i <= n; i++)if (v[i] == 0) {vect.push_back(i); for (int j = 2 * i; j <= n; j += i)v[j] = 1;} return vect;}

void solve(){
    int n , m; cin >> n >> m;
    if(m == 0) cout << 1 << nl;
    else if(m == n){
        cout << 0 << nl;
    }
    else cout << (min(n - m , m)) << nl;
}   

signed main(){
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    int t = 1; 
    // cin >> t;
    while(t--){
        solve();
    }
    return 0;   
}