get your ass back here

#include "pch.h"
#include <iostream>
#include <vector>

using namespace std;

double funct(double y, double t)
{
    return -25 * y + cos(t) + 25 * sin(t);
}

int main()
{
    double h,t=0;
    cin >> h;
    int n = 2 / h;
    double yt,yr;
    vector <double> y(n+1),y1(n+1),y2(n+1),y3(n+1);
    y[0] = 1;
    y1[0] = 1;
    y2[0] = 1;
    y3[0] = 1;
    for (int i = 0; i < n; i++,t+=h)
    {
        y[i + 1] = y[i] + h*funct(y[i], t);
        y1[i + 1] = y1[i] + h / 2 * (funct(y1[i], t) + funct(y1[i] + h * funct(y1[i], t), t + h));
        yt = y2[i] + h * funct(y2[i], t);
        yr = y3[i] + h * funct(y3[i], t);
        y2[i+1] = y2[i] + h * funct(yt, t+h);
        y3[i+1] = y3[i] + (h / 2)*(funct(y3[i], t) + funct(yr, t+h));
        while (abs(yt - y2[i]) >= 1e-12)
        {
            yt = y2[i+1];
            y2[i+1] = y2[i] + h * funct(yt, t+h);
        }
        while (abs(yr - y3[i]) >= 1e-12)
        {
            yr = y3[i+1];
            y3[i+1] = y3[i] + (h / 2)*(funct(y3[i], t) + funct(yr, t+h));
        }

    }
}