34 lines
996 B
C
34 lines
996 B
C
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#include <stdio.h>
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#include <time.h>
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// 函数声明
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long long sum_leijia(long long a, long long b);
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long long sum_gaosi(long long a, long long b);
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int main() {
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clock_t before, middle, after;
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long long a = 1LL, b = 100000000LL;
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long long result1 = 0LL, result2 = 0LL;
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before = clock();
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result1 = sum_leijia(a, b);
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middle = clock();
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printf("累加计算结果: %lld, 所用时间: %lf 毫秒\n", result1, (double)(middle - before) / CLOCKS_PER_SEC * 1000);
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// 计算公式方式的和并计时
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result2 = sum_gaosi(a, b);
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after = clock();
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printf("高斯求和结果: %lld, 所用时间: %lf 毫秒\n", result2, (double)(after - middle) / CLOCKS_PER_SEC * 1000);
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return 0;
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}
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long long sum_leijia(long long a, long long b) {
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long long sum = 0LL;
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for (long long i = a; i <= b; i++) {
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sum += i;
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}
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return sum;
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}
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long long sum_gaosi(long long a, long long b) {
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return (a + b) * (b - a + 1) / 2;
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}
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