Submission #76751560

Source Code Expand

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#include <stdio.h>
#define MOD_BY 998244353
int add(int a, int b) {
  return a + b - MOD_BY * (a + b >= MOD_BY);
}
char S[312345];
int memo[312345][4];
int calc(int pos, int prev) {
  int id = S[pos] - 'a';
  int ans = 0;
  if (id < 0 || 2 < id) return prev != 3;
  if (memo[pos][prev]) return ~memo[pos][prev];
  /* 入れない */
  ans = add(ans, calc(pos + 1, prev));
  /* 入れる */
  if (id != prev) ans = add(ans, calc(pos + 1, id));
  return ~(memo[pos][prev] = ~ans);
}
int main(void) {
  if (fgets(S, sizeof(S), stdin) == NULL) return 1;
  printf("%d\n", calc(0, 3));
  return 0;
}
 
 
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#include <stdio.h>

#define MOD_BY 998244353

int add(int a, int b) {
	return a + b - MOD_BY * (a + b >= MOD_BY);
}

char S[312345];

int memo[312345][4];

int calc(int pos, int prev) {
	int id = S[pos] - 'a';
	int ans = 0;
	if (id < 0 || 2 < id) return prev != 3;
	if (memo[pos][prev]) return ~memo[pos][prev];

	/* 入れない */
	ans = add(ans, calc(pos + 1, prev));
	/* 入れる */
	if (id != prev) ans = add(ans, calc(pos + 1, id));

	return ~(memo[pos][prev] = ~ans);
}

int main(void) {
	if (fgets(S, sizeof(S), stdin) == NULL) return 1;
	printf("%d\n", calc(0, 3));
	return 0;
}

Submission Info

Judge Result