Comet OJ - Contest #14 B

夕日的光辉
#include <stdio.h>
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <queue>
#include <stack>
#pragma GCC optimize(2)
 
#define mm(i,v) memset(i,v,sizeof i);
#define mp(a, b) make_pair(a, b)
#define one first
#define two second
 
using namespace std;
typedef long long ll;
typedef pair<int, int > PII;
 
const int N = 1e6 + 5, mod = 1e9 + 9, INF = 0x3f3f3f3f;
int t, n, p1, p2, p3, p4, flag;
char s[N];

int main()
{
    cin >> t;
    while (t--) {
        cin >> n;
        scanf("%s", s + 1);
        
        p1 = 0, p2 = 0, p3 = 0, p4 = 0;
        for (int i = 1; i <= n; ++i) {
            if (s[i] == 'p') p1 = 1;
            if (s[i] == 'i' && p1 != 0) p2 = 1;
            if (s[i] == 'n' && p2 != 0) p3 = 1;
            if (s[i] == 'k' && p3 != 0) {
                p4 = 1;
                break;
            }
        }
        if (p4 == 0) {
            puts("-1");
            continue;
        }
        
        flag = 0;
        for (int i = 1; i <= n; ++i) {
            if (flag == 0) {
                if (s[i] == 'p') {
                    p1 = i;
                    flag = 1;
                    continue;
                } else {
                    s[i] = 'a';
                    continue;
                }
            } else if (flag == 1) {
                if (s[i] == 'i') {
                    p2 = i;
                    break;
                } else {
                    s[i] = 'a';
                    continue;
                }
            }
        }
        
        flag = 0;
        for (int i = n; i >= 1; --i) {
            if (flag == 0) {
                if (s[i] == 'k') {
                    p4 = i;
                    flag = 1;
                    continue;
                } else {
                    s[i] = 'a';
                    continue;
                }
            } else if (flag == 1) {
                if (s[i] == 'n') {
                    p3 = i;
                    break;
                } else {
                    s[i] = 'a';
                    continue;
                }
            }
        }
        
        int Max = p3 - p2 - 1;
//        cout << p3 << "  " << p2 << endl;
        for (int i = p3 - 1; i >= 1; --i) {
            if (s[i] == 'i') {
                if (i - p1 - 1 > Max)
                {
                    Max = i - p1 - 1;
                }
                break;
            }
        }
        for (int i = p2 + 1; i <= n; ++i) {
            if (s[i] == 'n') {
                if (p4 - i - 1 > Max)
                {
                    Max = p4 - i - 1;
                }
                break;
            }
        }
        cout << Max << endl;
    }
}
/*
1
22
pinpipkinpkinpknninnpk
*/
来源：https://www.cnblogs.com/mwh123/p/11823557.html
标签