4 条题解

  • 0
    @ 2025-7-7 10:59:19

    //计算1!+2!-3!+4!-5!+……N!

    #include <stdio.h> #include <math.h>

    int main() { int n; int a = 1; int b = 0; int f = -1; int sum = 0; printf("计算1!+2!-3!+4!-5!+……N!\n"); printf("请输入N的值:"); scanf_s("%d", &n); if (n == 1) { sum = 1; } else { for (int i = 1; i <= n; i++) { for (int j = 1; j <= i; j++) { a = a * j; } sum = sum + (a * f); f = -f; a = 1; } // 计算-1!+2!-3!+4!-5!+……N!的值 sum = sum + 2; //由于原题的第一项为正值,需要加2 } printf("结果为:%d", sum); return 0; }

    • 0
      @ 2024-12-9 0:49:22

      #include<stdio.h>

      int main() { int t; scanf("%d", &t); while (t--) { int n; scanf("%d", &n); if (n == 1) { printf("1\n"); } else { long long sum = 1; for (int a = 2; a <= n; a++) { long long ans = 1; if (a % 2 == 0) { for (int b = 1; b <= a; b++) { ans *= b; } sum += ans; } else { for (int b = 1; b <= a; b++) { ans *= (-b); } sum += ans; }

      } printf("%lld\n", sum); }

      } return 0;

      }

      • 0
        @ 2024-10-21 8:49:58

        #include <stdio.h>

        int main()

        {

        int n;

        scanf("%d",&n);

        while(n--){

        int a;

        scanf("%d",&a);

        if(a==1){

        printf("%d\n",a);

        }else if(a==2){

        printf("%d\n",a+1);

        }else if(a>2){

        int ax=-1;

        long long int sum=2,sam=3,ma=2;

        for(int i=3;i<=a;i++){

        if(i%2!=0){

        ma=i*ma;

        sum=ma*ax+sam;

        sam=sum;

        ax=1;

        }else{

        ma=i*ma;

        sum=ma*ax+sam;

        sam=sum;

        ax=-1;

        }

        }

        printf("%lld\n",sum);

        }

        }

        return 0;

        }

        • 0
          @ 2023-10-19 20:39:13

          #include<stdio.h> int main(){ int t,n; scanf("%d",&t); for(int i=0;i<t;i++){ scanf("%d",&n); long long sum=1,sb=2; for(int j=1;j<=n;j++){ sum=jsum(-1); sb=sb+sum; } printf("%lld\n",sb); } return 0; }

          • 1

          信息

          ID
          180
          时间
          3000ms
          内存
          128MiB
          难度
          7
          标签
          (无)
          递交数
          719
          已通过
          192
          上传者