def ii(a = False):
i = input().split()
try:
if len(i) == 1 and not a:
return int(i[0])
return list(map(int, i))
except Exception:
if len(i) == 1 and not a:
return i[0]
return i
def gcd(a, b):
if a == 0:
return b
return gcd(b % a, a)
for _ in range(ii()):
n = ii()
s = input()
index = 0
for i in range(n):
if s[i]!='0':
index = i
break
t = 0
s = s[index:]
prev = s[0]
for i in s:
if prev!=i:
t+=1
prev = i
print(t)
#include <bits/stdc++.h>
#define int long long
#define vi vector<int>
#define pb push_back
#define inf INT_MAX
#define minf INT_MIN
#define mod 1000000007
#define bits1 __builtin_popcountl
#define fio \
ios_base::sync_with_stdio(NULL); \
cin.tie(NULL);
using namespace std;
signed main() {
fio int t ;
cin>>t;
while(t--)
{
int n ;
cin>>n ;
string str;
cin>>str ;
int flag=0 ;
int plag=0 ;
int ctr=0 ;
int ptr=0 ;
for(int i=0;i<n;i++)
{
if(str[i]=='1')
{
flag=1 ;
}
if(((str[i]=='0'&&(plag%2)==0)||(str[i]=='1'&&(plag%2)==1))&&flag)
{
ctr++ ;
plag++ ;
}
}
flag=0 ;
plag=0 ;
for(int i=0;i<n;i++)
{
if(((str[i]=='1'&&(plag%2)==0)||(str[i]=='0'&&(plag%2)==1)))
{
ptr++ ;
plag++ ;
}
}
cout<<min(ctr,ptr)<<"\n" ;
}
return 0;
}
1472B - Fair Division | 1281C - Cut and Paste |
141A - Amusing Joke | 112A - Petya and Strings |
677A - Vanya and Fence | 1621A - Stable Arrangement of Rooks |
472A - Design Tutorial Learn from Math | 1368A - C+= |
450A - Jzzhu and Children | 546A - Soldier and Bananas |
32B - Borze | 1651B - Prove Him Wrong |
381A - Sereja and Dima | 41A - Translation |
1559A - Mocha and Math | 832A - Sasha and Sticks |
292B - Network Topology | 1339A - Filling Diamonds |
910A - The Way to Home | 617A - Elephant |
48A - Rock-paper-scissors | 294A - Shaass and Oskols |
1213A - Chips Moving | 490A - Team Olympiad |
233A - Perfect Permutation | 1360A - Minimal Square |
467A - George and Accommodation | 893C - Rumor |
227B - Effective Approach | 1534B - Histogram Ugliness |