For each part below give a running time analysis using Big Oh notation?

$($a$)$

public static int minSubsum$($ int $[]$ a$)\{$

int minSum $=0,$ this Sum $=0$;

for $($int $j=0$; $j$ a$.$ length; $j++)\{$

thisSum $+=a[j]$;

if$($thisSum $$ minSum$)$

minSum $=$ thisSum;

else if$($thisSum $>0)$

thisSum $=0$;

$\}$

return minSum;

$\}$

$($b$)$

sum $=0$;

for $=$