求值（河南萌新2024）

我真的服了，注意数据范围！！！！！！！！！！！！！！！！！！！！ 

#include <bits/stdc++.h>using namespace std;
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef pair<int, int> pii;
typedef pair<ll, ll> PII;
#define pb emplace_back
//#define int ll
#define all(a) a.begin(),a.end()
#define x first
#define y second
#define ps push_back
#define endl '\n'
#define IOS ios::sync_with_stdio(0),cin.tie(0),cout.tie(0)void solve();const int N = 1e6 + 10;signed main() {IOS;ll t;cin >> t;while(t--)solve();return 0;
}void solve() {ll a,b,c,n,w;cin >> a >> b >> c >> n >> w;ll k1 = a-c,k2 = b-c;ll ans = LONG_LONG_MAX;for(int x = 0; x <= n; ++ x){ll f1,f2;ll pa1 = k1*x + c*n - w;ll l = 0,r = n-x;while(l <= r){ll lp = l + (r - l)/3;ll rp = r - (r - l)/3;f1 = abs(pa1 + k2*lp);f2 = abs(pa1 + k2*rp);if(f1 > f2)l = lp + 1;elser = rp - 1;}ans = min(ans,min(f1,f2));}cout << ans << endl;
}

三分y，其中z被消掉了，x是枚举，求导易得为常数，为线性函数。

void GordenGhost() {ll ans=inf;int a,b,c,n,w;cin>>a>>b>>c>>n>>w;
//    if (c>b) swap(b,c);for (int x = 0; x <= n ; ++x) {int l=0,r=n-x;while (l<r){int mid=(l+r)>>1;
//            if (x+mid>n){
//                r=mid-1;
//                continue;
//            }auto check = [&](int k){int kl=n-x-k;return abs(x*a+k*b+kl*c-w);};int m1=check(mid),m2=check(mid+1);if (m2>m1) r=mid;else l=mid+1;}
//        for(int i=l;i<=r;i++)ans= min(ans, abs(x*a+l*b+(n-x-l)*c-w));}cout<<ans<<'\n';
}