Submission #7897027

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Source Code Expand

#pragma GCC optimize(3,"Ofast","inline")
#define R register
#include<iostream>
#include<cstdio>
#include<algorithm>
const int MAXN=1e5+7;
struct node{
	int ser,l,r;
}classroom[MAXN];
int a[MAXN*3],n,m,sum;
bool vis[MAXN];
bool cmp(node x,node y) {
	return x.l<y.l;
}
int MAX(int a,int b){
	return a>b?a:b;
}
int main(void) {
	scanf("%d%d",&n,&m);
	sum=m;
	for(R int i=1; i<=m; i++) {
		scanf("%d%d",&classroom[i].l,&classroom[i].r);
		classroom[i].ser=i;
	}
	std::sort(classroom+1,classroom+m+1,cmp);
	int flag=1,flag_l=classroom[1].l;
	for(R int i=2; i<=m; i++) {
		if(classroom[i].l>flag_l){
			if(!vis[classroom[flag].ser]) {
				sum--;
				vis[classroom[flag].ser]=true;
			}
		} 	
		if(classroom[i].r>classroom[flag].r) {
			flag_l=MAX(flag_l,classroom[flag].r+1);
			flag=i;
		} else flag_l=MAX(flag_l,classroom[i].r+1);
	}
	if(flag_l<=classroom[flag].r){
		if(!vis[classroom[flag].ser]) {
			sum--;
			vis[classroom[flag].ser]=true;
		}
	} 
	printf("%d\n",sum);
	for(int i=1; i<=m; i++) 
		if(!vis[i]) 
			printf("%d\n",i);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:19:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
./Main.cpp:22:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&classroom[i].l,&classroom[i].r);
                                                ^

Judge Result