Submission #438876

#	Time	Username	Problem	Language	Result	Execution time	Memory
438876		Snowfall	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	35 ms	3040 KiB

ho_t2

#include<bits/stdc++.h>
using namespace std;
char arr[200005];
int a[1000];
int qs[3][200005];
main()
{
	int t,p;
    a['O']=1;
    a['I']=2;
    scanf("%d%d",&t,&p);
    scanf("%s",&arr[1]);
    for(int i = 1;i <= t;i++)
    {
        qs[a[arr[i]]][i]++;
        // printf("%d\n",arr[i]);
        for(int j = 0;j < 3;j++)
        qs[j][i]+=qs[j][i-1];
    }
    int mn=1e9;
    for(int i = 1;i <= t;i++)
    {
        int ck=0;
        int pv=i;
        int sm=0;
        for(int j = 0;j < 3 && ck==j;j++)
        {
            int st=pv,ed=t;
            int tmn=1e9;
            while(st<=ed)
            {
                int md=(st+ed)/2;
                // printf("%d %d<--\n",qs[j][md],qs[j][pv-1]);
                if(qs[j][md]-qs[j][pv-1]>=p)
                {
                    ed=md-1;
                    tmn=min(tmn,md);
                }
                else
                {
                    st=md+1;
                }
            }
            // printf("d %d %d %d\n",j,tmn,pv-1);
            if(tmn==1e9)
            break;
            if(qs[j][tmn]-qs[j][pv-1]==p)
            {
                sm+=tmn-pv+1-p;
                ck++;
                pv=tmn+1;
            }
            // printf("%d %d\n",pv,sm);
        }
        if(ck==3)
        mn=min(mn,sm);
    }
    if(mn!=1e9)
    printf("%d",mn);
    else
    printf("-1");
}

Compilation message (stderr)

ho_t2.cpp:6:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
    6 | main()
      | ^~~~
ho_t2.cpp: In function 'int main()':
ho_t2.cpp:15:19: warning: array subscript has type 'char' [-Wchar-subscripts]
   15 |         qs[a[arr[i]]][i]++;
      |              ~~~~~^
ho_t2.cpp:11:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     scanf("%d%d",&t,&p);
      |     ~~~~~^~~~~~~~~~~~~~
ho_t2.cpp:12:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     scanf("%s",&arr[1]);
      |     ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87