如何在LPSolve中实现二进制约束？

import lpsolve55 as lpsolve

# 创建LP问题
lp = lpsolve.lpsolve('make_lp', 0, num_of_variables)

# 设置目标函数
lpsolve.set_obj_fn(lp, objective_function)

# 添加变量
for i in range(num_of_variables):
    lpsolve.set_binary(lp, i+1, True)  # 设置变量为二进制类型

# 添加约束
for i in range(num_of_constraints):
    lpsolve.add_constraint(lp, constraint_matrix[i], lpsolve.LE, constraint_rhs[i])
    lpsolve.set_binary(lp, i+1, True)  # 设置约束为二进制类型

# 求解LP问题
lpsolve.solve(lp)

# 获取最优解
solution = lpsolve.get_variables(lp)

# 打印最优解
for i in range(num_of_variables):
    print(f"Variable {i+1}: {solution[i]}")

# 释放内存
lpsolve.delete_lp(lp)