prepare (1/3): 
finished

make (2/3): 
g++ -g -Wall -O2 -o P2.o -c P2.cpp 
P2.cpp: In function 'int main(int, const char**)':
P2.cpp:30:45: warning: 'result' may be used uninitialized in this function [-Wmaybe-uninitialized]
     cout<<"The order-"<<order<<" item is "<<result<<endl;
                                             ^~~~~~
g++ -g -Wall -O2 -o P2func.o -c P2func.cpp 
P2func.cpp: In function 'int P2partition_det(int*, int, int, int)':
P2func.cpp:68:23: warning: 'random' may be used uninitialized in this function [-Wmaybe-uninitialized]
     int pivot=a[random];
                       ^
g++ -g -Wall -O2 -o main P2.o P2func.o
finished

clean (3/3): 
finished

all task finished, build successfully