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void RK4_System(int n, double h, double t, double x[], int nsteps){	double y[n];	double k[4][n];	int i=0;	int j=0;	printf("0 %lf %lf\n",t,x[i]);	for(j=0;j<nsteps;j++)	{		XP_System(n,t,x,k[0]);		for(i=0;i<n;i++)		{			y[i]=x[i]+0.5*h*k[0][i];		}		XP_System(n,(t+(h/2)),y,k[1]);		for(i=0;i<n;i++)		{			y[i]=x[i]+0.5*h*k[1][i];		}		XP_System(n,(t+(h/2)),y,k[2]);		for(i=0;i<n;i++)		{			y[i]=x[i]+h*k[2][i];		}		XP_System(n,t+h,y,k[3]);		for(i=0;i<n;i++)		{			x[i]=x[i]+((h*(k[0][i]+(2*k[1][i])+(2*k[2][i])+k[3][i]))/6);		}		t=t+h;		printf("%d %lf %lf %lf\n",j,t,x[0], x[1]);	}}