很正确。我写了三个程序。第一个程序和第二个结果不一样，很诡异 @RISC @howfar @carmanlee @wtl

第一个程序，第二次断在右侧，能拼成三角形的概率是19.3%

第二个程序，第二次可能断在右侧，也可能断在左侧，能拼成三角形的概率是17%

第三个程序，同时断裂，答案25%

% 程序一
try_num = 1e5;
a = rand(1,try_num);
b = rand(1,try_num).*(1-a);
c= 1-a-b;
abc = [a; b; c];
abc_sort = sort(abc);

good = 0;
for ite = 1:try_num
    if abc_sort(3,ite) < 0.5
        good = good+1;
    end
end
ratio1 = good/try_num
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% 程序二
clear all
try_num = 1e5;
a = rand(1,try_num);
for ite =1:try_num
    if rand > 0.5
        b(ite) = rand.*(1-a(ite));
    else
        b(ite) = rand.*a(ite);
    end
end

c= 1-a-b;
abc = [a; b; c];
abc_sort = sort(abc);

good = 0;
for ite = 1:try_num
    if abc_sort(3,ite) < 0.5
        good = good+1;
    end
end
ratio2 = good/try_num

%%%%%%%%%%%%%%%%%%%
% 程序三
clear all
try_num = 1e9;

a = rand(2,try_num);
b = sort(a);
b0 = zeros(1,try_num);
b1 = ones(1,try_num);

bt = [b0; b ; b1];
c = diff(bt);
d = max(c);
ind = find(d<0.5);
ratio3 = length(ind)/try_num




【 在 fayewong 的大作中提到: 】
: y不一定断在另一节啊
--
修改:novicer FROM 49.93.126.*
FROM 49.93.126.*