各种算法（三）

function deleteIs(str){
  var index = str.search("is");
  var left = str.slice(0,index+2);
  var right = str.slice(index+2,str.length);
  right = right.split("is").join("");
  return left.concat(right);
 }

console.log(deleteIs("thisismybook"));//thismybook

Array.prototype.push = function(val){
    console.log(val);
}
var temp = [1,2,5];
temp.push(7);//打印7

 function getResult(arr,n,sum){
    if(n==0&&sum==0){
        return true;
    }
    if(n<0){
        return false;
    }
    if(n>0){
        for(var i in arr){
            var temp = arr.slice(i+1,arr.length);
            return getResult(temp,n-1,sum-arr[i]) || getResult(temp,n,sum);
        }
    }
}

console.log(getResult([1,2,3,4],2,7)); //true

function remove(str){
  var reg = /(^s+)|(s+?)/g;
  return str.replace(reg,"");
}

console.log(remove("this is book"));//"thisisbook"

function getSingleNumber(arr){
  var temp = [];
  for(var i in arr){
    if(temp.indexOf(arr[i]) == -1){
      temp.push(arr[i]);
    }else{
      temp.splice(temp.indexOf(arr[i]),1);
    }
  }
  return temp[0];
}

console.log(getSingleNumber([0,1,0,0])); //1

function merge(arr){
  var reg = /(.)1*/g;
  var str = arr.join("");
  str = str.replace(reg,"$1");
  arr = str.split("");
  arr = arr.map(function(val){
    return parseInt(val);
  })
  return arr;
}

console.log(merge([3,2,2,4,5,5,6,2,1]));//[3,2,4,5,6,2,1]