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Data Structures and Algorithms → Introduction to DSA 40

What is the output: cout<<(0b1010 ^ 0b1100);
6
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The output of: cout<<~0;
-1
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What is the output: int x=0x1234; cout<<((x>>8)&0xFF)<<" "<<(x&0xFF);
18 52
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The output of: float f=3.14f; int i=*(int*)&f; is:
A specific integer bit pattern (type punning)
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Which is correct for checking if number is even without %?
All equivalent
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The output of: int a=3,b=3; cout<<(a==b && !(a^b));
1
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To multiply by 4 using bit shift:
n<<2 (left shift by 2 = multiply by 2^2=4)
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To divide by 8 using bit shift:
n>>3 (right shift by 3 = divide by 2^3=8)
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The output of: int x=100; cout<<(x/10)<<(x%10);
100
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The output of: string s=""; for(int i=65;i<70;i++) s+=(char)i; cout<<s;
ABCDE
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Which OOP concept is violated when a class has public data members?
Encapsulation (data hiding)
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What is cohesion in software design?
Degree to which a class/module has a single, focused purpose
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What is coupling in software design?
Degree of interdependence between modules (lower is better)
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High cohesion and low coupling is:
Good design (focused modules, minimal interdependence)
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A God class (class that does everything) violates:
Single Responsibility Principle
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What is composition over inheritance principle?
Prefer building objects from components rather than inheriting
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Law of Demeter (Principle of Least Knowledge) says:
Object should only talk to immediate friends (not friends of friends)
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Which is an anti-pattern?
Singleton overuse, God class, Copy-paste programming
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The output of: class C{int x; public: C():x(0){} C(int x):x(x){} void print(){cout<<x;} }; C c1,c2(5); c1.print(); c2.print();
05
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The output of: class A{public:int x; A(int x):x(x){}}; A a(5); cout<<a.x;
5
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The output of: int f(int n){return n<=1 ? 1 : n*f(n-1);} cout<<f(5);
120
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The output of: int f(int n){return n<=1 ? n : f(n-1)+f(n-2);} cout<<f(7);
13
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The output of: int gcd(int a,int b){return b==0?a:gcd(b,a%b);} cout<<gcd(48,18);
6
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The output of: int power(int b,int e){return e==0?1:b*power(b,e-1);} cout<<power(2,8);
256
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Fast power (exponentiation by squaring) computes a^n in:
O(log n)
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The output of: int arr[]={5,3,8,1,9,2}; sort(arr,arr+6); cout<<arr[0]<<" "<<arr[5];
1 9
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The output of: int arr[]={1,2,3,4,5}; cout<<*max_element(arr,arr+5)<<" "<<*min_element(arr,arr+5);
5 1
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The output of: string s="Hello World"; transform(s.begin(),s.end(),s.begin(),toupper); cout<<s;
HELLO WORLD
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The output of: vector<int> v={1,2,3}; v.resize(5); cout<<v[4];
0
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The output of: string s="abcabc"; cout<<count(s.begin(),s.end(),a);
2
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The output of: cout<<boolalpha<<(3>2)<<" "<<(2>3);
true false
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What is the output: int x=42; cout<<hex<<x<<" "<<dec<<x;
2a 42
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The output of: int a[]={1,2,3,4,5}; cout<<sizeof(a)/sizeof(*a);
5
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The output of: vector<int> v={3,1,4,1,5,9}; sort(v.begin(),v.end()); v.erase(unique(v.begin(),v.end()),v.end()); cout<<v.size();
5
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What is the output: map<int,int> m={{1,10},{2,20},{3,30}}; for(auto [k,v]:m) cout<<k<<v;
102030
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The output of: auto v=vector<int>(5); iota(v.begin(),v.end(),1); cout<<v[3];
4
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The output of: int n=10; int sum=accumulate(begin({1,2,3,4,5,6,7,8,9,10}),end({1,2,3,4,5,6,7,8,9,10}),0); cout<<sum;
55
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The output of: string s="Race Car"; remove_if(s.begin(),s.end(),::isspace); cout<<s;
Race Car
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The output of: auto s=set<int>{5,3,1,4,2}; cout<<distance(s.begin(),s.end());
5
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The output of: int x=7; cout<<(x%2==0?"Even":"Odd")<<" "<<(x>0?"Pos":"NonPos");
Odd Pos
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