I’ve an issue with Monte Carlo, I wrote the code, nevertheless it fully doesn’t random, the result’s 0.
g is operate, p and okay is the decrease and higher restrict, n variety of random factors

That is the code i wolfram mathematica:

   x[g_, p_, k_, n_] := Module[{s, d, j, z},
    s = 0;
    d = p - k;
    For[j = 1, j <= n, j++,
    z = Random[Real, {p, 0}];
    s += g[p + z*d];
    ];
    s = d*s/n;
    Return[s]]


f[x_] := x*x + 2 x;
a = 0;
b = 1;
n = 500000;
x[g, p, k, n]

The lead to c ++ involves 1.333 in wolfram mathematica 0, I do not know the place the error is. I do not know how one can enhance it.