Submission #69062698

Source Code Expand

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#include <stdio.h>
#include <inttypes.h>
int N;
char S[512345 * 2];
int main(void) {
  int i, next;
  char wanted;
  uint64_t ans1 = 0, ans2 = 0;
  if (scanf("%d", &N) != 1) return 1;
  if (scanf("%1012344s", S) != 1) return 1;
  /* ABAB… にする */
  for (i = 0, next = 0, wanted = 'A'; i < 2 * N; i++) {
    if (S[i] == wanted) {
      if (next == i) {
        next++;
        wanted = wanted == 'A' ? 'B' : 'A';
      } else {
        ans1 += i - next;
 
 
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#include <stdio.h>
#include <inttypes.h>

int N;
char S[512345 * 2];

int main(void) {
	int i, next;
	char wanted;
	uint64_t ans1 = 0, ans2 = 0;
	if (scanf("%d", &N) != 1) return 1;
	if (scanf("%1012344s", S) != 1) return 1;

	/* ABAB… にする */
	for (i = 0, next = 0, wanted = 'A'; i < 2 * N; i++) {
		if (S[i] == wanted) {
			if (next == i) {
				next++;
				wanted = wanted == 'A' ? 'B' : 'A';
			} else {
				ans1 += i - next;
				next += 2;
			}
		}
	}

	/* BABA… にする */
	for (i = 0, next = 0, wanted = 'B'; i < 2 * N; i++) {
		if (S[i] == wanted) {
			if (next == i) {
				next++;
				wanted = wanted == 'A' ? 'B' : 'A';
			} else {
				ans2 += i - next;
				next += 2;
			}
		}
	}

	printf("%" PRIu64 "\n", ans1 <= ans2 ? ans1 : ans2);
	return 0;
}

/*

wanted: ABABAB
actual: BBAABA
        ABBABA ans1 += 2
        ABABBA ans1 += 1
        ABABAB ans1 += 1

wanted: ABABAB
actual: AAABBB

*/

Submission Info

Judge Result