[编程入门]求和训练-题解（C语言代码）

/*求第一个和时用某大数学家的方法*/

#include<stdio.h>

int main()

{

int a, b, c;

scanf("%d%d%d", &a, &b, &c);

float suma=0, sumb=0, sumc=0,sum;

if (a % 2 == 0)

{

float t = 0;

t = a / 2;

suma = (1 + a)*t;

}

else

{

float t = 0;

t = (a + 1) / 2;

suma = (1 + a)*t;

}

for (float i = 1; i <= b; i++)

{

sumb += i * i;

}

for (float i = 1; i <= c; i++)

{

sumc += 1 / i;

}

sum = suma + sumb + sumc;

printf("%.2f",sum);

return 0;

}