UVa 10341: Solve It: WA

    #include <bits/stdc++.h>
    using namespace std;
    #define d(x)                cout << #x << " = " << (x) << endl;
    #define fr                  freopen("in.txt", "r", stdin);
    #define fw                  freopen("out.txt", "w", stdout);
    #define mem(x)              memset((x), 0, sizeof((x)));
    #define pb                  push_back
    #define LL                  long long
    #define fastIO              ios_base::sync_with_stdio(false)
    #define sf                  scanf
    #define pf                  printf
    #define SQR(x)              ((x)*(x))
    #define sc1(x)              scanf("%d", &x)
    #define scb(x, y)           scanf("%d %d", &x, &y)
    #define sc3(x, y, z)        scanf("%d %d %d", &x, &y, &z)
    #define FOR(i, x, y)        for(int i=int(x); i<int(y); i++)
    #define ROF(i, x, y)        for(int i=int(x-1); i>=int(y); i--)
    #define all(c)              (c.begin(), c.end())
    #define unq(v)              sort(all(v)), (v).erase(unique(all(v)),v.end())
    #define EPSILON    (1.0E-9)
    #define siz 100000

    double p,q,r,s,t,u;
    double func(double x){
        double part1 = u;
        double part2 = t*x*x;
        double part3 = s*tan(x);
        double part4 = r*cos(x);
        double part5 = q*sin(x);
        double part6 = p*exp(-x);
        // return part1 + part2 + part3 + part4 + part5 + part6;
        return p*exp(-x) + q*sin(x) + r*cos(x) + s*tan(x) + t*x*x + u;
    }



    int main(){
        #ifndef ONLINE_JUDGE
            clock_t tStart = clock();
            freopen("in.txt", "r", stdin);
            freopen("out.txt", "w", stdout);
        #endif

            while(cin >> p >> q >> r >> s >> t >> u){

                double a = 0.0;
                double b = 1.0;

                double c = a;

                if (func(a) * func(b) > EPSILON){
                    cout << "No solution" << endl;
                    continue;
                }

                int it = 100;
                while(it--){
                    c = (a+b)/2.0;


                    if(func(c)*func(a) <= 0){
                        b = c;
                    }
                    else if(func(c)*func(b) < 0){
                        a = c;
                    }

                }

                printf("%0.4lf\n", c);
            }

        #ifndef ONLINE_JUDGE
            printf("\n>>Time taken: %.10fs\n", (double) (clock() - tStart) / CLOCKS_PER_SEC);
        #endif
    }