Submission #56303154

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

void justDoIt();

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    justDoIt();
    return 0;
}

void justDoIt() {
    int n;
    cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        char c;
        cin >> c;
        if (c == 'R') {
            a[i] = 0;
        }
        if (c == 'S') {
            a[i] = 1;
        }
        if (c == 'P') {
            a[i] = 2;
        }
    }
    vector<vector<int>> dp(n, vector<int>(3, -1));
    for (int i = 0; i < n; i++) {
        for (int j1 = 0; j1 < 3; j1++) {
            if ((a[i] + 1) % 3 == j1) {
                dp[i][j1] = -1;
                continue;
            }
            int score = (j1 != a[i]);
            if (i == 0) {
                dp[i][j1] = score;
                continue;
            }
            for (int j2 = 0; j2 < 3; j2++) {
                if (j1 != j2 && dp[i - 1][j2] != -1) {
                    dp[i][j1] = max(dp[i][j1], dp[i - 1][j2] + score);
                }
            }
        }
    }
    int res = 0;
    for (int j = 0; j < 3; j++) {
        res = max(res, dp[n - 1][j]);
    }
    cout << res;
}

Submission Info

Judge Result