【JavaScript】1-9任意插入加减号，值为100 ，如：1+23-4+56+7+8+9=100

 

 

//1-9任意插入加减号，值为100
//如：1+23-4+56+7+8+9=100

let s = new Set();  //设置相互独立的非重复值
while(true){
    let sum = "1" + ["","+","-"][Math.round(Math.random()*2)];  //相邻两个数之间随机加、减或无
    sum += "2" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "3" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "4" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "5" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "6" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "7" + ["","+","-"][Math.round(Math.random()*2)];
    sum += "8" + ["","+","-"][Math.round(Math.random()*2)] + "9";
    if(eval(sum) == 100){
        s.add(sum);     //add() 方法用来向一个 Set 对象的末尾添加一个指定的值
    }
    let index = "0";
    if(s.size == 11){      //这里我运算过有11个，做个判断跳出循环
        s.forEach(function(v,i){
            console.log(`${++index}.${v} = 100`);  //单引号，模板字符串
        })
        break;
    }
}