洛谷p1023

 

 

#include<stdio.h>

typedef struct product{
  int price;
  int sale;
}Product;

int main(void){
  int expect;
  int price, sale;
  int ogPrice, ogSale, maxPrice=0;
  Product p[10050];
  for(int i=0; i<10050; i++){
    p[i].sale = 0;
    p[i].price = 0;
  }
  scanf("%d", &expect);
  scanf("%d%d", &price, &sale);
  maxPrice = ogPrice = price;
  ogSale = sale;
  p[ogPrice].price = price;
  p[ogPrice].sale = sale;
  while(1){
    scanf("%d%d", &price, &sale);
    if(price==-1 && sale==-1)
      break;
    p[price].price = price;
    p[price].sale = sale;
    if(price > maxPrice)
      maxPrice = price;
  }
  int dec;
  Product be, af;//前驱后继
  scanf("%d", &dec);
  for(int i=ogPrice; i<10050; i++){
    if(p[i].price == 0){
      p[i].price = i;
      if(p[i].price > maxPrice)
        p[i].sale = p[i-1].sale - dec;
      else{
        for(int j=i-1; j>=ogPrice; j--){
          if(p[j].price != 0)//说明被赋过值
            be = p[j];
            break;
          }
        for(int j=i+1; j<10050; j++){
          if(p[j].price != 0){
            af = p[j];
            break;
          }
        }
        p[i].sale = be.sale+((af.sale - be.sale)/(af.price - be.price));
    }
  }
    if(p[i].sale <= 0)
      break;
  }
  int maxId = -1;
  int maxProfit = -1;
  int profit;
  int add = 0, minus = 0;
  while(maxId != expect && add < 10000){
    maxId = -1;
    maxProfit = -1;
    for(int i=ogPrice; i<10050; i++){
      if(p[i].sale <= 0)
        break;
      profit = (p[i].price-p[ogPrice].price+add)*p[i].sale;
      if(profit >= maxProfit){
        maxId = i;
        maxProfit = profit;
      }
    }
    add++;
  }
  if(maxId == expect)
    add--;
  else
    add = 100000;

  maxId = -1;
  maxProfit = -1;
  while(maxId != expect && minus*(-1) < 10000){
    maxId = -1;
    maxProfit = -1;
    for(int i=ogPrice; i<10050; i++){
      if(p[i].sale <= 0)
        break;
      profit = (p[i].price-p[ogPrice].price+minus)*p[i].sale;
      if(profit >= maxProfit){
        maxId = i;
        maxProfit = profit;
      }
    }
    minus--;
  }
  if(maxId == expect){
    ++minus;
  }
  else
    minus = -100000;

  if(add == 100000 && minus == -100000)
    printf("NO SOLUTION");
  else if(add < minus*(-1))
    printf("%d", add);
  else
    printf("%d", minus);

  return 0;
}