Description
N個矩形,排成一排. 現在希望用盡量少的矩形海報Cover住它們.
Input
第一行給出數字N,代表有N個矩形.N在[1,250000] 下面N行,每行給出矩形的長與寬.其值在[1,1000000000]2 1/2 Postering
Output
最少數量的海報數.
Sample Input
1 2
1 3
2 2
2 5
1 4
Sample Output
4Solve
單調棧+貪心
#include<cstdio>
int n,sta[250005],top,x,t,ans;
int main (){
scanf ("%d",&n);
for (int i=1;i<=n;++i,sta[++top]=x)
for (scanf ("%d%d",&t,&x);x<=sta[top];top--)
ans+=(x==sta[top]);
printf ("%d",n-ans);
}