bool canSplit(vector<int>& nums,int cut,long long max){

int accumulate=0;

for(auto num:nums){

if((accumulate+num)<=max)

accumulate+=num;

else{

cut--;

accumulate=num;

if(cut<0) return false;

}

}

return true;

}

int splitArray(vector<int>& nums, int m) {

long long right=0,left=0;

for(vector<int>::iterator it=nums.begin();it!=nums.end();it++){

left=max(left,(long long)*it);

right+=*it;

}

while(left<right){

long long mid=(left+right)/2;

if(canSplit(nums,m-1,mid)) right=mid;

else left=mid+1;

}

return left;

}