#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define ar array
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define vt vector
#define pb push_back
#define all(c) (c).begin(), (c).end()
#define sz(x) (int)(x).size()
#define F_OR(i, a, b, s) for (int i=(a); (s)>0?i<(b):i>(b); i+=(s))
#define F_OR1(e) F_OR(i, 0, e, 1)
#define F_OR2(i, e) F_OR(i, 0, e, 1)
#define F_OR3(i, b, e) F_OR(i, b, e, 1)
#define F_OR4(i, b, e, s) F_OR(i, b, e, s)
#define GET5(a, b, c, d, e, ...) e
#define F_ORC(...) GET5(__VA_ARGS__, F_OR4, F_OR3, F_OR2, F_OR1)
#define FOR(...) F_ORC(__VA_ARGS__)(__VA_ARGS__)
#define EACH(x, a) for (auto& x: a)
template<class T> bool umin(T& a, const T& b) {
return b<a?a=b, 1:0;
}
template<class T> bool umax(T& a, const T& b) {
return a<b?a=b, 1:0;
}
ll FIRSTTRUE(function<bool(ll)> f, ll lb, ll rb) {
while(lb<rb) {
ll mb=(lb+rb)/2;
f(mb)?rb=mb:lb=mb+1;
}
return lb;
}
ll LASTTRUE(function<bool(ll)> f, ll lb, ll rb) {
while(lb<rb) {
ll mb=(lb+rb+1)/2;
f(mb)?lb=mb:rb=mb-1;
}
return lb;
}
template<class A> void read(vt<A>& v);
template<class A, size_t S> void read(ar<A, S>& a);
template<class T> void read(T& x) {
cin >> x;
}
void read(double& d) {
string t;
read(t);
d=stod(t);
}
void read(long double& d) {
string t;
read(t);
d=stold(t);
}
template<class H, class... T> void read(H& h, T&... t) {
read(h);
read(t...);
}
template<class A> void read(vt<A>& x) {
EACH(a, x)
read(a);
}
template<class A, size_t S> void read(array<A, S>& x) {
EACH(a, x)
read(a);
}
string to_string(char c) {
return string(1, c);
}
string to_string(bool b) {
return b?"true":"false";
}
string to_string(const char* s) {
return string(s);
}
string to_string(string s) {
return s;
}
string to_string(vt<bool> v) {
string res;
FOR(sz(v))
res+=char('0'+v[i]);
return res;
}
template<size_t S> string to_string(bitset<S> b) {
string res;
FOR(S)
res+=char('0'+b[i]);
return res;
}
template<class T> string to_string(T v) {
bool f=1;
string res;
EACH(x, v) {
if(!f)
res+=' ';
f=0;
res+=to_string(x);
}
return res;
}
template<class A> void write(A x) {
cout << to_string(x);
}
template<class H, class... T> void write(const H& h, const T&... t) {
write(h);
write(t...);
}
void print() {
write("\n");
}
template<class H, class... T> void print(const H& h, const T&... t) {
write(h);
if(sizeof...(t))
write(' ');
print(t...);
}
void DBG() {
cerr << "]" << endl;
}
template<class H, class... T> void DBG(H h, T... t) {
cerr << to_string(h);
if(sizeof...(t))
cerr << ", ";
DBG(t...);
}
#ifdef _DEBUG
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif
template<class T> void offset(ll o, T& x) {
x+=o;
}
template<class T> void offset(ll o, vt<T>& x) {
EACH(a, x)
offset(o, a);
}
template<class T, size_t S> void offset(ll o, ar<T, S>& x) {
EACH(a, x)
offset(o, a);
}
mt19937 mt_rng(chrono::steady_clock::now().time_since_epoch().count());
ll randint(ll a, ll b) {
return uniform_int_distribution<ll>(a, b)(mt_rng);
}
template<class T, class U> void vti(vt<T> &v, U x, size_t n) {
v=vt<T>(n, x);
}
template<class T, class U> void vti(vt<T> &v, U x, size_t n, size_t m...) {
v=vt<T>(n);
EACH(a, v)
vti(a, x, m);
}
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
void solve() {
int n, k;
read(n, k);
string s;
read(s);
int a=0;
FOR(n/2)
a+=s[i]!=s[n-1-i];
print(abs(a-k));
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int t=1;
read(t);
FOR(t) {
write("Case #", i+1, ": ");
solve();
}
} Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!
OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}
C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
// code
}