Atcoder abc 139

Posted 2022-09-20 lyt020321

A

#include <bits/stdc++.h>
 
using namespace std ;
string s , t ;
int num ;
int main () 
    cin >> s >> t ;
    for(int i = 0 ; i < s.size() ; i ++) 
        if(s[i] == t[i]) num ++ ;
    
    cout << num << endl ;
    return 0 ;
   

---

B

#include <bits/stdc++.h>
 
using namespace std ;
int n , m , ans = 0 ;
int main () 
    cin >> n >> m ;
    if(m == 1) 
        cout << 0 << endl ;
        return 0 ;
    
    int c = 1 ;
    while(c < m) 
        c += n-1 ;
        ans ++ ;
    
    cout << ans << endl ;
    return 0 ;
   

---

C

#include <bits/stdc++.h>
 
using namespace std ;
int n , m , ans = 0 ,a[120000] ;
int main () 
    cin >> n ;int maxx = 0 , ans = 0 ;
    for(int i = 1 ; i <= n ; i ++) 
        cin >> a[i] ;
        if(a[i] <= a[i-1]) maxx ++ , ans = max(maxx,ans) ;
        else maxx = 0 ;
    
    cout << ans << endl ;
    return 0 ;
   

D

#include <bits/stdc++.h>
 
using namespace std ;
#define int long long
int n , m , ans = 0 ;
signed main () 
    cin >> n ;
    cout << n*(n-1)/2 << endl ;
    return 0 ;
   

E

#include <bits/stdc++.h>
#define int long long
#define maxn 1000010
using namespace std ;
struct dy 
    int y , next ;
A[maxn];
int n , num , cnt , tot, ans ;
int head[maxn] , a[1010][1010] , vis[1010][1010] ;
int in[maxn] , t[maxn] , day[maxn] ;
void add(int u,int v) 
    A[++cnt].y = v ;
    A[cnt].next = head[u] ;
    head[u] = cnt ;
    return ;

void topsort() 
    for(int i = 1 ; i <= tot ; i ++) 
        int u = t[i] ;
        for(int j = head[u] ; j ; j = A[j].next) 
            int v = A[j].y ;
            day[v] = day[u] + 1 ;
            in[v] -- ;
            if(!in[v])
                t[++tot] = v ;
        
    
    for(int i = 1 ; i <= num ; i ++)
         ans=max(ans,day[i]);
    return;

signed main() 
    scanf("%d",&n);
    for(int i = 1 ; i <= n ; i ++) 
        for(int j = 1 ; j < n ; j ++) 
            scanf("%d",&a[i][j]) ;
            if(!vis[i][j]&&!vis[j][i]) 
                vis[i][j] = vis[j][i] = ++num ;
        
    
    for(int i = 1 ; i <= n ; i ++) 
        for(int j = 2 ; j < n ; j ++) 
            add(vis[i][a[i][j-1]],vis[i][a[i][j]]);
            in[vis[i][a[i][j]]] ++ ;
        
    
    for(int i = 1 ; i <= num ; i ++)
      if(!in[i]) 
        t[++tot] = i ;
        day[i] = 1 ;
      
    topsort() ;
    if(tot != num) puts("-1");
    else printf("%d\n",ans);
    return 0;