2021牛客暑期多校训练营2-K（Stack）

​​https://ac.nowcoder.com/acm/contest/11253/K​​

​​详解请参考此处​​

​​AC代码​​

#include <iostream>

using namespace std;

int n, k, p, x;

int a[1000005], b[1000005], s[1000005];

int main(){

    scanf("%d%d", &n, &k);

    for (int i = 0; i < k; ++i) {
        scanf("%d%d", &p, &x);
        b[p] = x;
    }

    for (int i = 1; i <= n; ++i) {
        if(!b[i]){
            b[i] = b[i-1] + 1;
        }else if(b[i] > b[i-1] + 1){
            printf("-1\n");
            return 0;
        }
    }

    int cnt = 0, top = 0;
    for (int i = n; i >= 1; i--) {
        // 将数放入栈中,使其满足b[i]的条件
        while (b[i] > top){
            s[++top] = ++cnt;
        }

        a[i] = s[top];
        top--;
    }

    for (int i = 1; i <= n; ++i) {
        printf("%d ", a[i]);
    }
    return 0;
}