软件工程图

a;
do{
    b;
    if(X1){
        f;
        if(X4){
            do{
                i;
            }while(X5);
        }else{
            g;
            h;
        }
    }else{
        switch (X2){
            case 1:
                while(X3){
                	c
            	}
                break;
            case 2:
                d;
                break;
            case 3:
                e;
                break;
        }
    }
}while(!X6);
j;