SumSums from SPOJ

Author: kungfucat

SUMSUMS-h.cpp

@@ -0,0 +1,67 @@
+#include<iostream>
+using namespace std;
+
+#define mod 98765431
+int size=2;
+void multiply(long long int first[][3],long long int second[][3])
+{
+    long long int answer[10][10]={};
+    for(int i=0;i<size;i++){
+        for(int j=0;j<size;j++){
+            for(int k=0;k<size;k++){
+                answer[i][j]=answer[i][j] + (first[i][k]%mod * second[k][j]%mod)%mod;
+                answer[i][j]%=mod;
+            }
+        }
+    }
+    for(int i=0;i<size;i++){
+        for(int j=0;j<size;j++){
+            first[i][j]=answer[i][j];
+        }
+    }
+}
+
+void power(long long int second[][3],long long int n){
+    long long int current[3][3]={},i,j;
+    for(i=0;i<size;i++){
+        for(j=0;j<size;j++)
+            current[i][j]=second[i][j];
+    }
+    if(n<=1){
+        return;
+    }
+    if(n&1){
+         power(second,n-1);
+        multiply(second ,current);
+    }
+    else{
+        power(second,n/2);
+    multiply(second,second);
+    }
+}
+int main(){
+    int n,i;
+    long long int t;
+    long long int cows[50010],initial_sum=0;
+    cin>>n>>t;
+    for(int i=0;i<n;i++){
+        cin>>cows[i];
+        cows[i]%=mod;
+        initial_sum+=cows[i];
+        initial_sum%=mod;
+    }
+    long long int ans=0,myArray[3][3],newAnswer=0;
+    myArray[0][0]=n-1;myArray[0][1]=0;myArray[1][0]=1;myArray[1][1]=-1;
+    power(myArray,t);
+    // for(int i=0;i<size;i++){
+    //     for(int j=0;j<size;j++)
+    //         cout<<myArray[i][j]<<" ";
+    //     cout<<"\n";
+    // }
+    for(i=0;i<n;i++){
+        newAnswer=(myArray[1][0]%mod*initial_sum%mod)%mod + (myArray[1][1]%mod*cows[i]%mod)%mod; 
+        newAnswer=(newAnswer+mod)%mod;
+        cout<<newAnswer<<"\n";
+    }
+    return 0;
+}