2023寒假训练Week3

Day 1

AcWing 4455. 出行计划

通过差分的方式计算出每个时刻做核酸产生的贡献，然后\(O(1)\)的回答就好了

#include <bits/stdc++.h>

using namespace std;

const int N = 4e5+5;
int n , m , k , b[N];


int read(){
    int x = 0 , f = 1 , ch = getchar();
    while( (ch < '0' || ch > '9') && ch != '-' ) ch = getchar();
    if( ch == '-' ) f = -1 , ch = getchar();
    while( ch >= '0' && ch <= '9' ) x = ( x << 3 ) + ( x << 1 ) + ch - '0' , ch = getchar();
    return x * f;
}

int main(){
    n = read() , m = read() , k = read();
    for( int c , t ; n ; n -- )
        t = read() , c = read() , b[min( t+1 , N-1 )] -- , b[max(t-c+1,0)] ++;
    for( int i = 1 ; i < N ; i ++ ) b[i] += b[i-1];
    for( int q ; m ; m -- )
        q = read() + k , printf("%d\n" , b[q] );
    return 0;
}