2016-2017 ACM-ICPC Northwestern European Regional Programming Contest (NWERC 2016) personal solution to a problem

 

 

• Problem C Careful Ascent

The poor we were stuck in attendance question was half done with the results written about the speed interval [0,1e32], and change [-1e32,1e32] on the adoption, hey ~ how no think about the range of the interval to change it.

Here is the normal mathematical solution, similar to solving a linear equation.

#include <iostream>
using namespace std;
typedef long long ll;

ll x,y,n;
ll a,b;double c;
int main(){
    cin>>x>>y>>n;
    ll sum = y;
    double X = 0;
    while (n--){
        cin>>a>>b>>c;
        sum -= (b-a);
        X += (b-a)*c;
    }
    X += sum;
    printf("%.10f\n",(double)x/X);
    return 0;
}