Submission #75376526

Source Code Expand

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#include <stdio.h>
#include <stdlib.h>
int cmp(const void* x, const void* y) {
  int a = *(const int*)x, b = *(const int*)y;
  return (a > b) - (a < b);
}
int N;
int A[312345];
int dekimasuka(int last) {
  int i;
  int target;
  if (last < 1 || last % 2 == 0) return 0;
  target = A[0] + A[last];
  for (i = 1; i < last - i; i++) {
    if (A[i] + A[last - i] != target) return 0;
  }
  return 1;
}
int is_first = 1;
void kotaeru(int ans) {
  printf(" %d" + is_first, ans);
  is_first = 0;
}
int main(void) {
  int i;
  int firstmax;
  if (scanf("%d", &N) != 1) return 1;
  for (i = 0; i < N; i++) {
    if (scanf("%d",  &A[i]) != 1) return 1;
  }
  qsort(A, N, sizeof(*A), cmp);
  for (i = N - 1; A[i] == A[N - 1]; i--);
  firstmax = i + 1;
  if (
    (firstmax > 1 && A[0] + A[firstmax - 1] == A[N - 1] && dekimasuka(firstmax - 1)) ||
    firstmax == 0
 
 
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#include <stdio.h>
#include <stdlib.h>

int cmp(const void* x, const void* y) {
	int a = *(const int*)x, b = *(const int*)y;
	return (a > b) - (a < b);
}

int N;
int A[312345];

int dekimasuka(int last) {
	int i;
	int target;
	if (last < 1 || last % 2 == 0) return 0;
	target = A[0] + A[last];
	for (i = 1; i < last - i; i++) {
		if (A[i] + A[last - i] != target) return 0;
	}
	return 1;
}

int is_first = 1;
void kotaeru(int ans) {
	printf(" %d" + is_first, ans);
	is_first = 0;
}

int main(void) {
	int i;
	int firstmax;
	if (scanf("%d", &N) != 1) return 1;
	for (i = 0; i < N; i++) {
		if (scanf("%d",  &A[i]) != 1) return 1;
	}
	qsort(A, N, sizeof(*A), cmp);
	for (i = N - 1; A[i] == A[N - 1]; i--);
	firstmax = i + 1;
	if (
		(firstmax > 1 && A[0] + A[firstmax - 1] == A[N - 1] && dekimasuka(firstmax - 1)) ||
		firstmax == 0
	) {
		kotaeru(A[N - 1]);
	}
	if (dekimasuka(N - 1)) {
		kotaeru(A[0] + A[N - 1]);
	}
	putchar('\n');
	return 0;
}

/*

a + b = L
a を増やす → b を減らさなければならない

・最小と最大を組み合わせる (全部分かれた)
・最大が L で、最小とセカンドベストを組み合わせる

しかない

*/

Submission Info

Judge Result