由于輸入已經排序,自定義二進制搜索應該有效(您可能需要對邊緣情況進行一些更新,即請求的值小于數組的所有元素)：

function [result, res2] = binarySearchExample(val)

%// Generate example data and sort it

N = 100000000;

a = rand(N, 1);

a = sort(a);

%// Run the algorithm

tic % start timing of the binary search algorithm

div = 1;

idx = floor(N/div);

while(1)

div = div * 2;

%// Check if less than val check if the next is greater

if a(idx) <= val,

if a(idx + 1) > val,

result = a(idx + 1);

break

else %// Get bigger

idx = idx + max([floor(N / div), 1]);

end

end

if a(idx) > val, % get smaller

idx = idx - floor(N / div);

end

end % end the while loop

toc % end timing of the binary search algorithm

%% ------------------------

%% compare to MATLAB find

tic % start timing of a matlab find

j = find(a > val, 1);

res2 = a(j);

toc % end timing of a matlab find

%// Benchmark

>> [res1, res2] = binarySearchExample(0.556)

Elapsed time is 0.000093 seconds.

Elapsed time is 0.327183 seconds.

res1 =

0.5560

res2 =

0.5560