add

public/c/ch1/compare.c

@@ -0,0 +1,21 @@
+#include <stdio.h>
+#include <time.h>
+
+int main() {
+    long timea, timeb, timec;//clock_t timea;
+    long a = 1LL, b = 100000000LL;
+    long long result1 = 0LL, result2 = 0LL;  
+
+    timea = clock();    
+    for (long long i = a; i <= b; i++) {
+        result1 += i;    
+    }
+    timeb = clock();    
+    printf("累加结果: %lld, 所用时间: %lf 毫秒\n", result1, (double)(timeb - timea) / CLOCKS_PER_SEC * 1000);
+
+    result2 = (a + b) * (b - a + 1) / 2;
+    timec = clock();    
+    printf("高斯结果: %lld, 所用时间: %lf 毫秒\n", result2, (double)(timec - timeb) / CLOCKS_PER_SEC * 1000);    
+ 
+    return 0; 
+}