Submission #6429604

---

Source Code Expand

//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
#define mem(a,v) memset((a), (v), sizeof (a))
#define enl printf("\n")
#define case(t) printf("Case #%d: ", (t))
#define ni(n) scanf("%d", &(n))
#define nl(n) scanf("%lld", &(n))
#define nai(a, n) for (int i = 0; i < (n); i++) ni(a[i])
#define nal(a, n) for (int i = 0; i < (n); i++) nl(a[i])
#define pri(n) printf("%d\n", (n))
#define prl(n) printf("%lld\n", (n))
#define pii pair<int, int>
#define pil pair<int, long long>
#define pll pair<long long, long long>
#define vii vector<pii>
#define vil vector<pil>
#define vll vector<pll>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define mp make_pair
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef cc_hash_table<int,int,hash<int>> ht;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> oset;
const double pi = acos(-1);
const int MOD = 998244353;
const int INF = 1e9 + 7;
const int MAXN = 2e5 + 5;
const double eps = 1e-9;
char str[MAXN];
int dp[MAXN][3][3]; // ind, sm, last, two cons

void add(int& a, int b) {
	a = (a+b) % MOD;
}

int main() {
	scanf("%s", str);
	int n = strlen(str);
	if (n == 2) return !pri(str[0] == str[1] ? 1 : 2);
	if (n == 3) {
		if (str[0] == str[1] && str[1] == str[2])
			return !pri(1);
		if (str[0] != str[1] && str[1] != str[2]) {
			if (str[0] == str[2])
				return pri(8);
			return pri(3);
		}
		return pri(7);
	}
	bool fl = 1, fl2 = 1;
	int sm = 0;
	ll p2 = 1;
	for (int i = 0; i < n; i++) {
		fl &= str[i] == str[0];
		sm = (sm+str[i]-'a')%3;
		if (i) {
			fl2 &= (str[i] != str[i-1]);
			p2 = (p2 * 3ll) % MOD;
		}
	}
	if (fl) return !pri(1);
	for (int i = 0; i < 3; i++)
		dp[1][i][i] = 1;
	for (int i = 1; i < n; i++)
		for (int nx = 0; nx < 3; nx++)
			for (int j = 0; j < 3; j++) // sm
				for (int k = 0; k < 3; k++) // last
					if (k != nx)
						add(dp[i+1][(j+nx)%3][nx], dp[i][j][k]);

	int ans = (dp[n][sm][0]+dp[n][sm][1]) % MOD;
	ans = (ans + dp[n][sm][2]) % MOD;
	ans = (p2 - ans + MOD) % MOD;
	if (fl2) ans = (ans+1) % MOD;
	pri(ans);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:45:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s", str);
                  ^

Judge Result