#include<stdio.h>#include<stdlib.h>#include<fcntl.h>#include<pthread.h>#include<math.h>#include<time.h>int threadnum = 1025;int n = 0;//n is less than threadnumint A[1025], B[1025][1025], C[1025][1025];struct param{int i;int j;int value;}param;int input(){int i = 0, j = 0;//printf("input the element number of array A: ");scanf("%d", &n);printf("size = %d\n", n);if(n == 0) return 0;A[0] = 0;//printf("init the array of A:\n");for(i=0; i<n; i++)scanf("%d", &A[i]);return 1;}void output(){int i, j;printf("matrix B:\n");for(i=0; i<=(int)(log(n)/log(2)); i++){for(j=0; j<(int)(n/pow(2, i)); j++)printf("%3d ", B[i][j]);printf("\n");}printf("matrix C\n");for(i=0; i<=(int)(log(n)/log(2)); i++){for(j=0; j<(int)(n/pow(2, i)); j++)printf("%3d ", C[i][j]);printf("\n");}}void *initMatrixB(void *arg){struct param *data = (struct param *)arg;int j = data->j;B[0][j] = data->value;//printf("B[0][%d] = %d ", j, B[0][j]);free(data);data = NULL;pthread_exit(0);}void *caculateB(void *arg){struct param *data = (struct param *)arg;int h = data->i;int j = data->j;B[h][j] = B[h-1][2*j] + B[h-1][2*j+1];//printf("B[%d][%d]=%d ", h, j, B[h][j]);free(data);data = NULL;pthread_exit(0);}void *caculateC(void *arg){struct param *data = (struct param *)arg;int h = data->i;int j = data->j;if(j == 0){C[h][0] = B[h][0];//printf("C[%d][%d]=%d ", h, j, C[h][j]);}else if(j%2 != 0){C[h][j] = C[h+1][j/2];//printf("C[%d][%d]=%d ", h, j, C[h][j]);}else{C[h][j] = C[h+1][(j-1)/2] + B[h][j];//printf("C[%d][%d]=%d ", h, j, C[h][j]);}free(data);data = NULL;pthread_exit(0);}int main(int argc, char **argv){clock_t start, end;freopen("data.dat", "r", stdin);while(input()){int i, j, h;start = clock();pthread_t threadids[threadnum];//printf("init matrix B\n");for(i=0; i<n; i++){struct param *data = (struct param *)malloc(sizeof(struct param));data->i = 0;data->j = i;data->value = A[i];pthread_create(&threadids[i], NULL, initMatrixB, (void *)data);}for(i=0; i<n; i++){pthread_join(threadids[i], NULL);}//printf("caculate matrix B\n");for(h=1; h<=(int)(log(n*1.0)/log(2*1.0)); h++){for(j=0; j<(int)(n/pow(2, h)); j++){struct param *data = (struct param *)malloc(sizeof(struct param));data->i = h;data->j = j;data->value = 0;pthread_create(&threadids[j], NULL, caculateB, (void *)data);}for(i=0; i<(int)(n/pow(2, h)); i++){pthread_join(threadids[i], NULL);}}//printf("caculate matrix C\n");for(h=(int)(log(n*1.0)/log(2*1.0)); h>=0; h--){for(j=0; j<(int)(n/pow(2*1.0, h*1.0)); j++){struct param *data = (struct param *)malloc(sizeof(struct param));data->i = h;data->j = j;data->value = 0;pthread_create(&threadids[j], NULL, caculateC, (void *)data);}for(i=0; i<(int)(n/pow(2*1.0, h*1.0)); i++){pthread_join(threadids[i], NULL);}}end = clock();//output();printf("the non-Recursive prefix sum algorithm runs %f seconds\n", (double)(end-start)/CLOCKS_PER_SEC);}return 0;}
