题目描述

输入

输出

摘自题解。。orz我还是太菜了

#include
      
       using namespace std;typedef long long LL;#define m first#define w secondconst int SIZE=1e5+7;int c[SIZE];struct shoe{  int w,m;} p[SIZE];inline int lowbit(int x) {  return x&-x;}void update(int x) {  for(;x
       
        0;x-=lowbit(x)) res+=c[x];  return res;}bool cmp(shoe s1,shoe s2){  return (s1.m < s2.m);}int main(){  freopen("test.in","r",stdin);  int n,M,W;  while((scanf("%d%d%d",&n,&M,&W)!= EOF))  {    for(int i=0;i
        
         =0;r--) {      for(;l
         
          <=M;++l)        update(p[l].w);      if(W-p[r].w>0) ans+=query(W-p[r].w);    }    for(int i=0;i