矩阵连乘分别用备忘录递归和动态规划解决

#include <stdio.h>#include <time.h>int main(void){clock_t start, end;long i, j = 1;start = clock();for( i = 0; i <= 1000000000; ++i ) {j *= 1024 * 1024 * 1024;j /= 1024 * 1024 * 1024;}end = clock();printf("time=%f/n", (double)(end-start)/CLOCKS_PER_SEC);start = clock();for( i = 0; i <= 1000000000; ++i ) {j <<= 30;j >>= 30;}end = clock();printf("time=%f/n", (double)(end-start)/CLOCKS_PER_SEC);printf("%d/n", j);return 0;}