Problem Link : http://www.spoj.com/problems/SUMSUM/
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This one is a interesting problem. The main idea behind the problem is combinatorics. At first we need to count the number of 1 bit and number of 0 bit in the i_th position of a given number. Then we need to do some combinatorial calculation.
Now think about an array of 4 number A=[1,0,1,0]. If we perform OR operation in the range 1 to 4 what will we get? We get 5 as answer. If we form pair from this number and perform OR operation between then then we will get the answer. Now as here is 4 element so we can perform pair in 4*(4-1)/2 = 6 ways. Now comes the tricky part. For OR operation how many pair will contribute nothing ?? Here is 2 zero and we can form 1 pair from this two element who will not contribute anything. So for i_th bit position the contribution for OR operation is number_of_active_pair*(2^i).
For AND operation we need to consider the number of pair can be form by 1 bit and for XOR the number of pair will be number_of_one_bit*number_of_zero_bit.
We can consider a number as an array of 30 element whose value is either 0 or 1 and perform above operation.
#include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> #define pii pair <int,int> #define pll pair <long long,long long> #define sc scanf #define pf printf #define Pi 2*acos(0.0) #define ms(a,b) memset(a, b, sizeof(a)) #define pb(a) push_back(a) #define MP make_pair #define db double #define ll long long #define EPS 10E-10 #define ff first #define ss second #define sqr(x) (x)*(x) #define D(x) cerr<<#x " = "<<(x)<<endl #define VI vector <int> #define DBG pf("Hi\n") #define MOD 1000000007 #define CIN ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0) #define SZ(a) (int)a.size() #define sf(a) scanf("%d",&a) #define sfl(a) scanf("%lld",&a) #define sff(a,b) scanf("%d %d",&a,&b) #define sffl(a,b) scanf("%lld %lld",&a,&b) #define sfff(a,b,c) scanf("%d %d %d",&a,&b,&c) #define sfffl(a,b,c) scanf("%lld %lld %lld",&a,&b,&c) #define stlloop(v) for(__typeof(v.begin()) it=v.begin();it!=v.end();it++) #define loop(i,n) for(int i=0;i<n;i++) #define loop1(i,n) for(int i=1;i<=n;i++) #define REP(i,a,b) for(int i=a;i<b;i++) #define RREP(i,a,b) for(int i=a;i>=b;i--) #define TEST_CASE(t) for(int z=1;z<=t;z++) #define PRINT_CASE printf("Case %d: ",z) #define LINE_PRINT_CASE printf("Case %d:\n",z) #define CASE_PRINT cout<<"Case "<<z<<": " #define all(a) a.begin(),a.end() #define intlim 2147483648 #define infinity (1<<28) #define ull unsigned long long #define gcd(a, b) __gcd(a, b) #define lcm(a, b) ((a)*((b)/gcd(a,b))) using namespace std; //using namespace __gnu_pbds; //typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; /*----------------------Graph Moves----------------*/ //const int fx[]={+1,-1,+0,+0}; //const int fy[]={+0,+0,+1,-1}; //const int fx[]={+0,+0,+1,-1,-1,+1,-1,+1}; // Kings Move //const int fy[]={-1,+1,+0,+0,+1,+1,-1,-1}; // Kings Move //const int fx[]={-2, -2, -1, -1, 1, 1, 2, 2}; // Knights Move //const int fy[]={-1, 1, -2, 2, -2, 2, -1, 1}; // Knights Move /*------------------------------------------------*/ /*-----------------------Bitmask------------------*/ //int Set(int N,int pos){return N=N | (1<<pos);} //int reset(int N,int pos){return N= N & ~(1<<pos);} bool check(int N,int pos){return (bool)(N & (1<<pos));} /*------------------------------------------------*/ #define mx 100005 int tree[28][mx]; void update(int id, int idx, int val) { for(;idx<mx && idx;idx+=idx&-idx) tree[id][idx]+=val; } ll query(int id, int idx) { ll ret=0; for(;idx;idx-=idx&-idx) ret+=tree[id][idx]; return ret; } int ara[mx]; int main() { // freopen("in.txt","r",stdin); // freopen("out.txt","w",stdout); int n,q; sff(n,q); for(int i=1;i<=n;i++) sf(ara[i]); for(int i=1;i<=n;i++) { for(int j=0;j<28;j++) { if(check(ara[i],j)) update(j,i,1); } } while(q--) { int a,b,c; sf(a); if(a==1) { sff(b,c); for(int i=0;i<28;i++) { if(check(ara,i)) update(i,c,-1); } ara=b; for(int i=0;i<28;i++) { if(check(ara,i)) update(i,c,1); } } else { char ss[10]; scanf(" %s",&ss); string str=string(ss); sff(b,c); ll temp[30]; for(int i=0;i<28;i++) { temp[i]=query(i,c); } for(int i=0;i<28;i++) { temp[i]-=query(i,b-1); } ll ans=0; for(int i=0;i<28;i++) { ll one=temp[i]; ll zero=(c-b+1)-one; ll pairs=0; if(str=="OR") { ll total=one+zero; pairs=(total*(total-1))/2; pairs-=(zero*(zero-1))/2; } else if(str=="AND") { pairs=(one*(one-1))/2; } else if(str=="XOR") { pairs=one*zero; } ans+=(1LL<<i)*pairs; } printf("%lld\n",ans); } } return 0; }