# TRAVELPS - Editorial

Author: Daanish Mahajan
Tester: Istvan Nagy
Editorialist: Aman Dwivedi

Cakewalk

None

# PROBLEM:

Chef is going on a road trip and needs to apply for inter-district and inter-state travel e-passes. It takes A minutes to fill each inter-district e-pass application and B minutes for each inter-state e-pass application.

His journey is given to you as a binary string S of length N where 0 denotes crossing from one district to another district (which needs an inter-district e-pass), and a 1 denotes crossing from one state to another (which needs an inter-state e-pass).

Find the total time Chef has to spend on filling the various forms.

# EXPLANATION:

Just do as the problem says and calculate the time spent on filling the various forms. As the problem says that 0 denotes crossing from one district to another district which needs an inter-district e-pass that requires A minutes to fill the form, and 1 denotes crossing from one state to another which needs an inter-state e-pass which requires B minutes to fill the form. Hence

Let Z is the count of the number of zeroes present in the string and O is the count of the number of ones present in the string. Hence our answer will be:

ans = Z*A+O*B

Finally, we can output our answer.

# TIME COMPLEXITY:

O(|S|) per test case, where |S| is the length of the string.

# SOLUTIONS:

Author
``````#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define pb push_back
#define rb pop_back
#define ti tuple<int, int, int>
#define pii pair<int, int>
#define pli pair<ll, int>
#define pll pair<ll, ll>
#define mp make_pair
#define mt make_tuple

using namespace std;

const int maxt = 100, maxn = 100, maxa = 100, maxb = 100;
const string newln = "\n", space = " ";

int main()
{
int t;
int n;
string s;
int cost[2];
cin >> t;
while(t--){
cin >> n >> cost[0] >> cost[1] >> s;
int ans = 0;
for(char c : s){
assert(c >= '0' && c <= '1');
ans += cost[c - '0'];
}
cout << ans << endl;
}
}
``````
Tester
``````#include <iostream>
#include <cassert>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <random>

#ifdef HOME
#include <windows.h>
#endif

#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define forn(i, n) for (int i = 0; i < (int)(n); ++i)
#define for1(i, n) for (int i = 1; i <= (int)(n); ++i)
#define ford(i, n) for (int i = (int)(n) - 1; i >= 0; --i)
#define fore(i, a, b) for (int i = (int)(a); i <= (int)(b); ++i)

template<class T> bool umin(T& a, T b) { return a > b ? (a = b, true) : false; }
template<class T> bool umax(T& a, T b) { return a < b ? (a = b, true) : false; }

using namespace std;

long long readInt(long long l, long long r, char endd) {
long long x = 0;
int cnt = 0;
int fi = -1;
bool is_neg = false;
while (true) {
char g = getchar();
if (g == '-') {
assert(fi == -1);
is_neg = true;
continue;
}
if ('0' <= g && g <= '9') {
x *= 10;
x += g - '0';
if (cnt == 0) {
fi = g - '0';
}
cnt++;
assert(fi != 0 || cnt == 1);
assert(fi != 0 || is_neg == false);

assert(!(cnt > 19 || (cnt == 19 && fi > 1)));
}
else if (g == endd) {
assert(cnt > 0);
if (is_neg) {
x = -x;
}
assert(l <= x && x <= r);
return x;
}
else {
assert(false);
}
}
}

string readString(int l, int r, char endd) {
string ret = "";
int cnt = 0;
while (true) {
char g = getchar();
assert(g != -1);
if (g == endd) {
break;
}
cnt++;
ret += g;
}
assert(l <= cnt && cnt <= r);
return ret;
}
long long readIntSp(long long l, long long r) {
}
long long readIntLn(long long l, long long r) {
}
string readStringLn(int l, int r) {
}
string readStringSp(int l, int r) {
}

int main(int argc, char** argv)
{
#ifdef HOME
if (IsDebuggerPresent())
{
freopen("../in.txt", "rb", stdin);
freopen("../out.txt", "wb", stdout);
}
#endif
forn(tc, T)
{
int res = 0;
for (char c : S)
{
assert(c == '0' || c == '1');
if (c == '0')
res += A;
else
res += B;
}
printf("%d\n", res);
}
assert(getchar() == -1);
return 0;
}

``````
Editorialist
``````#include<bits/stdc++.h>
using namespace std;

#define int long long

void solve()
{
int n,a,b;
cin>>n>>a>>b;

string s;
cin>>s;

int ans = 0;

for(int i=0;i<n;i++)
{
if(s[i]=='0')
ans+=a;
else
ans+=b;
}

cout<<ans<<endl;
}

int32_t main()
{
// freopen("input.txt","r",stdin);
// freopen("output.txt","w",stdout);

int t;
cin>>t;

while(t--)
solve();

return 0;
}
``````