hdu 题目2034（水题），2036（水，简单计算多边形面积）,2037(水，贪心，会场安排类)

Dear 丶 2022-09-17 11:20 153阅读 0赞

[http://acm.hdu.edu.cn/showproblem.php?pid=2034][http_acm.hdu.edu.cn_showproblem.php_pid_2034]

#include<stdio.h>
    #include<iostream>
    #include<string.h>
    #include<algorithm>
    using namespace std;
    int a[110],c[110],n,mark[110];
    
    int find(int b){
    	for(int i=0;i<n;i++){
    		if(a[i]==b) return i;
    	}
    	return -1;
    }
    int main()
    {
    	int j,k,cnt,m,i,b;
    	while(scanf("%d%d",&n,&m),n||m){
    		
    		memset(mark,0,sizeof(mark));
    		
    		for(i=0;i<n;i++)
    			scanf("%d",&a[i]);
    			
    		for(i=cnt=0;i<m;i++){
    			scanf("%d",&b);
    			k = find(b);
    	//		cout<<k<<endl;
    			if(k>=0){
    				mark[k]=1;
    				cnt++;
    			}
    		}
    		if(n==cnt)puts("NULL");
    		else{
    			for(i=j=0;i<n;i++)
    				if(!mark[i]) c[j++] = a[i];
    			sort(c,c+j);
    			for(i=0;i<j;i++)
    				printf("%d ",c[i]);
    			puts("");
    		}
    	}
    	return 0;
    }

http://acm.hdu.edu.cn/showproblem.php?pid=2036[点击打开链接][Link 1]

http://blog.csdn.net/hpu\_zyh/article/details/9920197[点击打开链接][Link 2]计算多边形面积

#include <stdio.h>
    
    struct point{
    	int x,y;
    }p[105];
    
    double cross(point a,point b){
    	return a.x*b.y - a.y*b.x; 
    }
    int main()
    {
    	int n,i;double sum;
    	while(scanf("%d",&n),n){
    		for(i=0;i<n;i++){
    			scanf("%d%d",&p[i].x,&p[i].y);
    		}
    		sum=0;
    		for(i=0;i<n-1;i++){
    			sum += cross(p[i],p[i+1]);
    		}
    		sum += cross(p[n-1],p[0]);
    		sum /= 2.0;
    		printf("%.1lf\n",sum>0?sum:-sum);
    	}
    	return 0;
    }

[http://acm.hdu.edu.cn/showproblem.php?pid=2037][http_acm.hdu.edu.cn_showproblem.php_pid_2037]

#include<stdio.h>
    #include<iostream>
    #include<string.h>
    #include<algorithm>
    using namespace std;
    struct match{
    	int s,e;
    }a[105];
    bool cmp(match i,match j){
    	return i.e<j.e;
    }
    int main()
    {
    	int cnt,n,i,last;
    	while(scanf("%d",&n),n){
    			
    		for(i=0;i<n;i++)	scanf("%d%d",&a[i].s,&a[i].e);
    		sort(a,a+n,cmp);
    //		for(i=0;i<n;i++)	printf("i=%d,s=%d,e=%d\n",i,a[i].s,a[i].e);
    		last = a[0].e;
    		for(cnt=i=1;i<n;i++){
    			if(a[i].s>=last){	cnt++;	last = a[i].e;	} 
    		}
    		printf("%d\n",cnt);
    	}
    	return 0;
    }

[http_acm.hdu.edu.cn_showproblem.php_pid_2034]: http://acm.hdu.edu.cn/showproblem.php?pid=2034
[Link 1]: http://acm.hdu.edu.cn/showproblem.php?pid=2036
[Link 2]: http://blog.csdn.net/hpu_zyh/article/details/9920197
[http_acm.hdu.edu.cn_showproblem.php_pid_2037]: http://acm.hdu.edu.cn/showproblem.php?pid=2037