Submission #3430698

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Source Code Expand

#include<cstdio>
#include<algorithm>
using namespace std;
const int N=150010;
const int maxlog=17;
const int inf=0x7fffffff;
int n,q,better[N],f[N][20];
struct Work{
	int l,r;
	Work(){}
	Work(int a,int b){l=a;r=b;}
	bool operator < (const Work&a) const {
		if(l!=a.l) return l<a.l;
		return r<a.r;
	}
}work[N];
struct Peo{
	int l,r;
}peo[N];
int main()
{
	scanf("%d%d",&n,&q);
	for(int i=1;i<=n;i++)
		scanf("%d%d",&work[i].l,&work[i].r);	
	sort(work+1,work+1+n);
	work[n+1]=(Work){inf,inf};
	better[n+1]=n+1;
	for(int i=n;i>=1;i--){
		better[i]=better[i+1];
		if(work[i].r<work[better[i]].r)
			better[i]=i;
	}
	for(int i=1;i<=n;i++)
		f[i][0]=better[lower_bound(work+1,work+1+n,Work(work[i].r,0))-work];
	for(int i=1;i<=maxlog;i++)
		for(int j=1;j<=n;j++)
			f[j][i]=f[f[j][i-1]][i-1];
	for(int i=1,a,b;i<=q;i++){
		scanf("%d%d",&a,&b);
		int pos=better[lower_bound(work+1,work+1+n,Work(a,0))-work];
		if(work[pos].r>b) {
			printf("0\n");
			continue;
		}
		int ans=0;
		for(int i=maxlog;i>=0;i--)
			if(f[pos][i]&&work[f[pos][i]].r<=b){
				ans|=(1<<i);
				pos=f[pos][i];
			}
		printf("%d\n",ans+1);
	}
	fclose(stdin);
	fclose(stdout);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:22:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&q);
                     ^
./Main.cpp:24:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&work[i].l,&work[i].r); 
                                      ^
./Main.cpp:39:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&a,&b);
                      ^

Judge Result