C++编程。。长见识篇

1034: 求值 Time Limit:  1 Sec   Memory Limit:  128 MB

Submit: 191   Solved: 14
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Description

求Sn=1!+2!+3!+4!+5!+…+n!之值，其中n是一个数字。

Input

n

Output

和

Sample Input

5

Sample Output

153

#include <iostream>
#include <stdio.h>

using namespace std;

long long int sum;
long long int item;
int main()
{
    long long int n;
    scanf("%lld",&n);
    long long int i;
        sum = 0;
        item = 1;
        for(i = 1; i <= n; i ++)
        {
            item *= i;
            sum = sum + item;
        }
        printf("%lld\n",sum);

    return 0;
}

类型名称        字节数    取值范围
signed char       1        -128～+127
short int         2        -32768～+32767
int               4        -2147438648～+2147438647

long int          4        -2147438648～+2141438647

long long int  8      -9223372036854775808～+9223372036854775807

长见识了。。