Submission #223375

#	Time	Username	Problem	Language	Result	Execution time	Memory
223375		rainy	Lampice (COCI19_lampice)	C++17	0 / 110	26 ms	2048 KiB

lampice

#include<bits/stdc++.h>
#define MAXN 50005
#define pb push_back
using namespace std;
typedef vector<int> vi;
int N,A,B;
char c[MAXN];
map<char,vi> mp;
int nx[MAXN];

int main(){
    scanf("%d",&N);
    for(int i=0;i<N;i++){
        scanf(" %c",&c[i]);
        mp[c[i]].pb(i);
    }
    for(int i=0;i<N;i++){
        auto it=upper_bound(mp[c[i]].begin(), mp[c[i]].end(),i);
        if(it==mp[c[i]].end())nx[i]=-1;
        else nx[i]=*it;
    }
    for(int i=0;i<N-1;i++){
        scanf("%d%d",&A,&B);
        assert(abs(A-B)==1);
    }
    int si=0;
    int ans=1;
    for(int j=1;j<N;j++){
        if(nx[j]!=nx[j-1]-1){
            if(nx[j-1]-(j-1)==1){
                ans=max(ans, 2*(j-si));
            }
            else if(nx[j-1]-(j-1)==2){
                ans=max(ans, 2*(j-si)+1);
            }
            si=j;
        }
    }
    printf("%d\n",ans);
    return 0;
}

Compilation message (stderr)

lampice.cpp: In function 'int main()':
lampice.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&N);
     ~~~~~^~~~~~~~~
lampice.cpp:14:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf(" %c",&c[i]);
         ~~~~~^~~~~~~~~~~~~
lampice.cpp:23:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&A,&B);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 17
• Subtask 2: 0 / 25
• Subtask 3: 0 / 31
• Subtask 4: 0 / 37