# 计算圆周率PI * 服务器地址 172.16.192.24 * 用户名 2019301110060 * 计算圆周率 ```c #include #include double step; int main(){ static long num_steps; printf("请输入一个1000以上的数字求取PI值\n>>"); scanf("%ld",&num_steps); clock_t start_t, end_t; double total_t; int i; double x,pi,sum =0.0; start_t = clock(); step=1.0/(double)num_steps; //将1平分成100000步 for(i=1;i<=num_steps;i++){ x=(i-0.5)*step;//获得0-1的连续值 sum+=4.0/(1.0+x*x); } pi =step * sum; // end_t = clock(); total_t=(double)(end_t - start_t)/CLOCKS_PER_SEC; printf("运行时间为%fs\t%.10f\r\n",total_t,pi); return 0; } ``` * 加上时间和精度的控制 ```c #include #include double step; int main() { static long num_steps; // printf("请输入一个1000以上的数字求取PI值\n>>"); // scanf("%ld",&num_steps); for (num_steps = 1000000; num_steps <= 10000000; num_steps += 100000) { int index; index = ((double)num_steps - 1000000) / 100000 + 4; clock_t start_t, end_t; double total_t; int i; double x, pi, sum = 0.0; start_t = clock(); step = 1.0 / (double)num_steps; //将1平分成100000步 for (i = 1; i <= num_steps; i++) { x = (i - 0.5) * step; //获得0-1的连续值 sum += 4.0 / (1.0 + x * x); } pi = step * sum; // end_t = clock(); total_t = (double)(end_t - start_t) / CLOCKS_PER_SEC; printf("运行时间为%fs\t%.*f\r\n", total_t, pi, index); } return 0; } ``` * 输出结果 ```bash 运行时间为0.020000s 3.1416 运行时间为0.020000s 3.14159 运行时间为0.010000s 3.141593 运行时间为0.020000s 3.1415927 运行时间为0.020000s 3.14159265 运行时间为0.030000s 3.141592654 运行时间为0.020000s 3.1415926536 运行时间为0.030000s 3.14159265359 运行时间为0.020000s 3.141592653590 运行时间为0.030000s 3.1415926535899 运行时间为0.030000s 3.14159265358999 运行时间为0.030000s 3.141592653589834 运行时间为0.040000s 3.1415926535896115 运行时间为0.030000s 3.14159265358955730 运行时间为0.040000s 3.141592653589722062 运行时间为0.040000s 3.1415926535897442662 运行时间为0.030000s 3.14159265358982242589 运行时间为0.040000s 3.141592653589698969085 运行时间为0.050000s 3.1415926535897624738425 运行时间为0.040000s 3.14159265358961103942192 运行时间为0.050000s 3.141592653589609707154295 运行时间为0.040000s 3.1415926535896288029903189 运行时间为0.050000s 3.14159265358963946113135535 运行时间为0.050000s 3.141592653589633687971627296 运行时间为0.050000s 3.1415926535896367965960962465 运行时间为0.050000s 3.14159265358973316395463371009 运行时间为0.060000s 3.141592653589739825292781461030 运行时间为0.060000s 3.1415926535896865345875994535163 运行时间为0.050000s 3.14159265358964034930977504700422 运行时间为0.060000s 3.141592653589700301353104805457406 运行时间为0.060000s 3.1415926535896829818739206530153751 运行时间为0.070000s 3.14159265358976158566406411409843713 运行时间为0.060000s 3.141592653590072448110959157929755747 运行时间为0.060000s 3.1415926535893832216572718607494607568 运行时间为0.070000s 3.14159265358984018945420757518149912357 运行时间为0.070000s 3.141592653589813544101616571424528956413 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://zpliu.gitbook.io/booknote/bing-hang-ji-suan/01.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.