clc
clear all
s='aggcacggaaaaacgggaataacggaggaggacttggcacggcattacacggaggacgaggtaaaggaggcttgtctacggccggaagtgaagggggatatgaccgcttgg';
Ls=length(s);
Na=0;
Nc=0;
Ng=0;
Nt=0;
for i=1:Ls
if s(i)=='a'
Na=Na+1; %統計字符a的個數
elseif s(i)=='c'
Nc=Nc+1; %統計字符c的個數
elseif s(i)=='g'
Ng=Ng+1; %統計字符g的個數
elseif s(i)=='t'
Nt=Nt+1; %統計字符t的個數
end
end
fprintf('a的個數為%d\n c的個數為%d\n g的個數為%d\n t的個數為%d\n',Na,Nc,Ng,Nt); %輸出統計結果