Submission #220361

#	Time	Username	Problem	Language	Result	Execution time	Memory
220361		giorgikob	Horses (IOI15_horses)	C++14	0 / 100	1593 ms	12288 KiB

horses

typedef long long ll;

const int mod = 1e9+7;
int jump[1000000];
//int beg[1000000];
int X[1000000];
int Y[1000000];
int N;

int get_idx(int l,int r){

        if(l == r){
                return l;
        }

        int mid = l+r;
        mid >>= 1;
        int x = get_idx(l,mid);
        int y = get_idx(mid+1,r);

        ll cnt = 1;
        for(int i = x+1; i <= y; i++){
                if(jump[i] != -1){
                        i = jump[i];
                        continue;
                }
                cnt *= X[i];
                if(cnt > Y[x]){
                        break;
                }
        }

        return (cnt > Y[x]) ? y : x;
}

int calc(int pos){
        ll cnt = 1;
        for(int i = 0; i < pos; i++){
                cnt *= X[i];
                cnt %= mod;
        }
        cnt *= Y[pos];
        cnt %= mod;
        return (int)cnt;
}

void go(){

        for(int i = 0; i < N; i++){
                if(X[i] == 1){
                        int l = i;
                        while(i+1 < N && X[i+1] == 0) i++;
                        while(l != i) jump[l] = i, l++;
                }
        }
}

int init(int n, int x[], int y[]) {

        N = n;
        for(int i = 0; i < N; i++){
                jump[i] = -1;
                //beg[i] = -1;
                X[i] = x[i];
                Y[i] = y[i];
        }

        go();

        int idx = get_idx(0,N);

	return calc(idx);
}

int updateX(int pos, int val) {

        X[pos] = val;

        go();

        int idx = get_idx(0,N);

	return calc(idx);
}

int updateY(int pos, int val) {

        Y[pos] = val;

        int idx = get_idx(0,N);

	return calc(idx);
}

• Subtask 1: 0 / 17
• Subtask 2: 0 / 17
• Subtask 3: 0 / 20
• Subtask 4: 0 / 23
• Subtask 5: 0 / 23