Car

#include <bits/stdc++.h>

using namespace std;

double calcVal(double init)
{
        return exp(init) + sqrt(init);
}

double diff(double a, double b)
{
        return abs(a-b);
}

int main() {
        double d;
        cin >> d;

        double ma = 6;
        double mi = 0;
        double best = 999999;
        double bestX = 3;
        double minDiff = 0.0000000001;

        while (true) {
                double curX = (ma+mi) / 2.00;
                double curD = calcVal(curX);
                double diffDs = diff(curD, d);

                if (diffDs < minDiff) break;

                if (diffDs < best) {
                        best = diffDs;
                        bestX = curX;
                }

                if (curD > d) {
                        ma = curX;
                } else {
                        mi = curX;
                }

        }

        cout.precision(9);
        cout << bestX << "\n";
        return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED