Submission #56176

#	Time	Username	Problem	Language	Result	Execution time	Memory
56176		aquablitz11	Linear Garden (IOI08_linear_garden)	C++14	100 / 100	292 ms	62464 KiB

linear_garden

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

const int N = 1000010;
const int INF = 1e9;

int n, m;
char str[N];
int dp[N][15];

inline int add(int a, int b) { return (a+b)%m; }
inline int pos(int mn, int mx, int bal)
{
    if (mn == 0) {
        if (mx == 0) return 0;
        if (mx == 1) return 1+bal;
        if (mx == 2) return 3+bal;
    } else if (mn == -1) {
        if (mx == 0) return 7+bal;
        if (mx == 1) return 9+bal;
    } else if (mn == -2) {
        if (mx == 0) return 13+bal;
    }
    return 14;
}

int main()
{
    scanf("%d%d %s", &n, &m, str);
    for (int i = n; i >= 0; --i) {
        for (int mn = -2; mn <= 0; ++mn) {
            for (int mx = max(mn, 0); mx-mn <= 2; ++mx) {
                for (int bal = mn; bal <= mx; ++bal) {
                    int j = pos(mn, mx, bal);
                    if (i == n) dp[i][j] = 1;
                    else dp[i][j] = add(dp[i+1][pos(min(mn, bal-1), mx, bal-1)], dp[i+1][pos(mn, max(mx, bal+1), bal+1)]);
                }
            }
        }
    }
    
    int mn = 0, mx = 0, bal = 0, ans = 1;
    for (int i = 0; i < n; ++i) {
        if (str[i] == 'P') {
            ans = add(ans, dp[i+1][pos(min(mn, bal-1), mx, bal-1)]);
            ++bal;
            mx = max(mx, bal);
        } else {
            --bal;
            mn = min(mn, bal);
        }
    }
    printf("%d\n", ans);

    return 0;
}

Compilation message (stderr)

linear_garden.cpp: In function 'int main()':
linear_garden.cpp:29:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d %s", &n, &m, str);
     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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