HDU 3450 & HDU 2836 tree Array

Source: http://acm.hdu.edu.cn/showproblem.php? PID = 1, 3450

Question: give some numbers and ask how many sets are there. The absolute value of the difference between adjacent numbers is less than D.

Idea: Tree array. After finding the upper and lower bounds, it is the same as HDU 2227. The method for finding the upper and lower bounds is binary.

Code:

#include <iostream>#include <cstdio>#include <string.h>#include <algorithm>using namespace std;const int N = 100010;const int mod = 9901;struct dit{int id,value,xuhao;}dd[N],tempdd[N];int cnt[N],dp[N];bool cmp(dit a,dit b){return a.value < b.value;}int binary_search(int x,int lp,int rp){int mid = 0,ans = 1;while(lp <= rp){   mid = (lp + rp) / 2;   if(tempdd[mid].value > x)   rp = mid - 1;   else{   ans = mid;   lp = mid + 1;   }}return ans;}int binary_search2(int x,int lp,int rp){int ans = 1;while(lp <= rp){   int mid = (lp + rp) / 2;   if(tempdd[mid].value >= x){      rp = mid - 1;  ans = mid;   }   else   lp = mid + 1;}return ans;}int lowbit(int x){return x & (-x);}int sum(int x){int s = 0;while(x > 0){   s += cnt[x];   if(s >= mod)   s = s % mod;   x -= lowbit(x);}return s;}void update(int x,int add){while(x < N){   cnt[x] += add;   if(cnt[x] >= mod)   cnt[x] = cnt[x] % mod;   x += lowbit(x);}}int Bin(int x,int lp,int rp){while(lp <= rp){   int mid = (lp + rp) >> 1;   if(tempdd[mid].value == x)   return mid;   else if(tempdd[mid].value < x)   lp = mid + 1;   else   rp = mid - 1;}return -1;}int main(){//freopen("1.txt","r",stdin);int n,d;while(scanf("%d%d",&n,&d) != EOF){memset(cnt,0,sizeof(cnt));memset(dp,0,sizeof(dp));for(int i = 1; i <= n; ++i){    scanf("%d",&dd[i].value);dd[i].id = i;tempdd[i] = dd[i];}sort(tempdd+1,tempdd+n+1,cmp);int k = tempdd[1].id;int total = 0;for(int i = 1; i <= n; ++i){if(tempdd[i].value != tempdd[i-1].value || i == 1){   tempdd[++total].value = tempdd[i].value;}}int ans = 0;for(int i = 1; i <= n; ++i){int id = Bin(dd[i].value,1,total);   int x = dd[i].value - d;   int y = dd[i].value + d;   int xid = 0,yid = 0;   xid = binary_search2(x,1,total);   yid = binary_search(y,1,total);   int s1 = (sum(yid) - sum(xid - 1));   if(s1 < 0)   s1 += mod;   if(s1 >= mod)   s1 = s1 % mod;   ans = ans + s1 + 1;   if(ans >= mod)   ans = ans % mod;   update(id,(s1 + 1)%mod);}printf("%d\n",((ans - n) % mod + mod ) % mod);}return 0;}