Submission #2242805

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Source Code Expand

#include <algorithm>
#include <cstring>
#include <cstdio>
#define my_abs(x) ((x) < 0 ? -(x) : (x))
typedef long long ll; 
int n, q, a, b; 
ll seg1[200005], seg2[200005], dp[200005], dt; 
inline void modify1(int pos, ll x)
{
	for (; pos <= n; pos += pos & -pos)
		seg1[pos] = std::min(seg1[pos], x); 
}
inline void modify2(int pos, ll x)
{
	for (; pos; pos -= pos & -pos)
		seg2[pos] = std::min(seg2[pos], x); 
}
inline ll query1(int pos)
{
	ll res = 1e18; 
	for (; pos; pos -= pos & -pos)
		res = std::min(res, seg1[pos]); 
	return res; 
}
inline ll query2(int pos)
{
	ll res = 1e18; 
	for (; pos <= n; pos += pos & -pos)
		res = std::min(res, seg2[pos]); 
	return res; 
}
int main()
{
	// freopen("ARC073-F.in", "r", stdin); 
	scanf("%d%d%d%d", &n, &q, &a, &b); 
	memset(dp, 0x3f, sizeof(dp)); 
	memset(seg1, 0x3f, sizeof(seg1)); 
	memset(seg2, 0x3f, sizeof(seg2)); 
	dp[b] = 0; 
	modify1(b, -b); 
	modify2(b, b); 
	while (q--)
	{
		b = a; 
		scanf("%d", &a); 
		ll cur = std::min(query1(a) + a, query2(a) - a) + dt; 
		dt += my_abs(a - b); 
		if (cur - dt < dp[b])
		{
			dp[b] = cur - dt; 
			modify1(b, dp[b] - b); 
			modify2(b, dp[b] + b); 
		}
	}
	ll ans = 1e18; 
	for (int i = 1; i <= n; i++)
		ans = std::min(ans, dp[i]); 
	printf("%lld\n", ans + dt);
	return 0; 
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:35:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d%d%d", &n, &q, &a, &b); 
                                   ^
./Main.cpp:45:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a); 
                  ^

Judge Result