[luoguP2434] [SDOI2005]区间（贪心）

传送门

简单贪心

——代码

 #include <cstdio>
 #include <iostream>
 #include <algorithm>

 int n, l, r;
 struct node
 {
     int x, y;
 }p[];

 inline bool cmp(node x, node y)
 {
     return x.x < y.x;
 }

 inline int max(int x, int y)
 {
     return x > y ? x : y;
 }

 int main()
 {
     int i;
     scanf("%d", &n);
     for(i = ; i <= n; i++) scanf("%d %d", &p[i].x, &p[i].y);
     std::sort(p + , p + n + , cmp);
     l = p[].x;
     r = p[].y;
     for(i = ; i <= n; i++)
     {
         if(p[i].x > r)
         {
             printf("%d %d\n", l, r);
             r = ;
         }
         if(!r)
         {
             l = p[i].x;
             r = p[i].y;
         }
         else r = max(r, p[i].y);
     }
     printf("%d %d\n", l, r);
     return ;
 }