Submission #1220992

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Source Code Expand

#include <cstdio>
#include <cstring>
#include <cassert>
#include <iostream>
#include <algorithm>
#include <vector>
#include <set>

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) FOR (i, 0, n)
#define _ << " _ " <<
#define TRACE(x) cerr << #x << " = " << x << endl
#define debug(...) fprintf(stderr, __VA_ARGS__)
//#define debug
//#define TRACE(x)

using namespace std;

typedef long long llint;

const int MAXN = 100010;

int n, a[MAXN], dp[MAXN], inc[MAXN], dc[MAXN];

int main(void) {
  scanf("%d",&n);
  REP(i, n) scanf("%d",&a[i]);

  for (int i = n - 1; i >= 0; --i) {
    inc[i] = dc[i] = i;
    if (i + 1 < n && a[i] <= a[i+1])
      inc[i] = max(inc[i], inc[i+1]);
    if (i + 1 < n && a[i] >= a[i+1])
      dc[i] = max(dc[i], dc[i+1]);
    dp[i] = MAXN;
    dp[i] = min(dp[i], dp[inc[i] + 1] + 1);
    dp[i] = min(dp[i], dp[dc[i] + 1] + 1);
  }

  printf("%d\n",dp[0]);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:26:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&n);
                 ^
./Main.cpp:27:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   REP(i, n) scanf("%d",&a[i]);
                              ^

Judge Result