Codeforces Round #581 (Div. 2)

A

# include <bits/stdc++.h>
using namespace std;
​
int main()
{
    string s;
    cin>>s;
    int len=s.size();
    int ans=0;
    int flag=0;
    for(int i=0;i<len;i++){
        if(s[i]=='1'){
            if(ans==0){
                ans=(len-i)/2;
                if((len-i-1)%2==0) flag=1;
            }else if(flag){
                ans++;
                break;
            }else break;
        }
    }
    printf("%d\n",ans);
    return 0;
}
​

B

# include <bits/stdc++.h>
using namespace std;
​
int main()
{
    int n,l,r;
    scanf("%d%d%d",&n,&l,&r);
    int a=1;
    int minn=0;
    for(int i=1;i<=l;i++){
        minn+=a;
        a=a*2;
    }
    minn+=(n-l);
    int b=1;
    int maxx=0;
    for(int i=1;i<=r;i++){
        maxx+=b;
        b=b*2;
    }
    b=b/2;
    maxx+=(n-r)*b;
    printf("%d %d\n",minn,maxx);
    return 0;
}
​

C

# include <bits/stdc++.h>
using namespace std;
​
const int MAXN=110;
const int MAXX=1e6+100;
int m[MAXN][MAXN];
int p[MAXX];
int main()
{
    int n;
    scanf("%d",&n);
    memset(m,MAXX,sizeof(m));
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            char aaaa;
            aaaa=getchar();
            if(aaaa=='1') m[i][j]=1;
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            for(int k=1;k<=n;k++){
                m[i][j]=min(m[i][j],m[i][k]+m[k][j]);
            }
        }
    }
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cout<<m[i][j]<<" ";
        }
        cout<<endl;
    }

    int m;
    scanf("%d",&m);
    for(int i=1;i<=m;i++) scanf("%d",&p[i]);

    return 0;
}
​

D

# include <bits/stdc++.h>
using namespace std;
​
int main()
{
    string s;
    long long ans=0;
    cin>>s;
    for(int i=s.size()-1;i>=0;i--){
        if(s[i]=='0') ans++;
        else{
            if(ans) ans--;
            else s[i]='0';
        }
    }
    cout<<s<<endl;
    return 0;
 } 
​