Submission #3000809

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
#define N 200100
#define INF 0x3f3f3f3f

int n,c0,q,x,y;
int b[N],cost[N],d[N<<2],dp[N];
vector<int> v[N];

int query(int o,int L,int R,int l,int r) {
	if (l<=L && r>=R) return d[o];
	int mid=(L+R)>>1,ret=INF;
	if (l<=mid) ret=min(ret,query(o<<1,L,mid,l,r));
	if (r>mid) ret=min(ret,query(o<<1|1,mid+1,R,l,r));
	return ret;
}

void upd(int o,int l,int r,int x,int y) {
	if (l==r) {d[o]=min(d[o],y); return;}
	int mid=(l+r)>>1;
	if (x<=mid) upd(o<<1,l,mid,x,y);
	else upd(o<<1|1,mid+1,r,x,y);
	d[o]=min(d[o<<1],d[o<<1|1]);
}

int main()
{
	scanf("%d",&n);
	for (int i=1;i<=n;i++)
	{
		scanf("%d",&b[i]);
		if (!b[i]) c0++;
		cost[i]=b[i] ? 1 : -1;
	}
	scanf("%d",&q);
	for (int i=1;i<=q;i++)
	{
		scanf("%d%d",&x,&y);
		v[x].push_back(y);
	}
	memset(d,0x3f,sizeof(d));
	memset(dp,0x3f,sizeof(dp));
	dp[0]=0;
	for (int i=1;i<=n;i++)
	{
		for (int j=0;j<(int)v[i].size();j++)
		{
			int x=v[i][j];
			int t=min(dp[i-1],query(1,1,n,max(i-1,1),x));
			if (t<dp[x]) {
				dp[x]=t;
				upd(1,1,n,x,t);
			}
		}
		dp[i]=min(dp[i],dp[i-1]+cost[i]);
	}
	printf("%d\n",dp[n]+c0);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:28:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:31:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&b[i]);
                    ^
./Main.cpp:35:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&q);
                ^
./Main.cpp:38:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&x,&y);
                      ^

Judge Result