Submission #233712

#	Time	Username	Problem	Language	Result	Execution time	Memory
233712		duality	JJOOII 2 (JOI20_ho_t2)	C++11	100 / 100	28 ms	5504 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
typedef long long int LLI;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef vector<pii> vpii;

char S[200000];
int pre[3][200001],n[3][200001];
int main() {
    int i,j;
    int N,K;
    scanf("%d %d",&N,&K);
    for (i = 0; i < N; i++) {
        scanf(" %c",&S[i]);
        for (j = 0; j < 3; j++) pre[j][i+1] = pre[j][i];
        if (S[i] == 'J') pre[0][i+1]++;
        else if (S[i] == 'O') pre[1][i+1]++;
        else pre[2][i+1]++;
    }

    int ans = 1e9;
    j = 0;
    for (i = 0; i < N; i++) {
        while (pre[0][i+1]-pre[0][j] >= K) j++;
        n[0][i] = j-1;
    }
    j = 0;
    for (i = 0; i < N; i++) {
        while (pre[1][i+1]-pre[1][j] >= K) j++;
        n[1][i] = j-1;
    }
    j = 0;
    for (i = 0; i < N; i++) {
        while (pre[2][i+1]-pre[2][j] >= K) j++;
        n[2][i] = j-1;
    }
    for (i = 0; i < N; i++) {
        int u = n[2][i]-1;
        if (u >= 0) u = n[1][u]-1;
        else u = -2;
        if (u >= 0) u = n[0][u]-1;
        else u = -2;
        if (u != -2) ans = min(ans,i-u);
    }
    if (ans == 1e9) printf("-1\n");
    else printf("%d\n",ans-3*K);

    return 0;
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:15:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d",&N,&K);
     ~~~~~^~~~~~~~~~~~~~~
ho_t2.cpp:17:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf(" %c",&S[i]);
         ~~~~~^~~~~~~~~~~~~

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