JAVA-階乘算法

單個數階乘 

public static void jieCheng(){
    //6!
    long jc = 1;
    for(int = 1; i<=6;i++){
    jc *= i;
    }
    System.out.print("6!爲："+jc);
}

 

遞歸寫法(遞歸寫法很是簡便)

public static long diGuiJieCheng(int n){
    if(n<1)return -1;
    if(n == 0 || n == 1)  return 1;
    return n*diGuiJieCheng(n-1);
}

 

 

 

多個階乘相加

0!+1!+4!+7!+...+16!

public static void jieCheng(){

int jc0=1;
long sumJc = jc0;
for(int i = 1;i<=16;i+=3){
long jc=1;
for(int j = 1;j<=i;j++){
 jc *=j;
}
sumJc += jc;

}
System.out.print(sumJc)


}