fruitsv3.cpp

#include <bits/stdc++.h>

using namespace std;

int main() {


    // INPUT SECTION



    int N=0; // number of days

    scanf("%d", &N);

    int G[N+10];// array of fruits - all
    int E[N+10];//number of fruits you can eat
    int K=0; // day number that will expire - after day 1 the fruits to eat at day 0 will expire.
    int Et=0; // total fruits can eat - for prevention of nest
    // On day 1, day 0's fruits are still good when K=1.
    // On day 2, day 0's fruits are still good when K=2.

    // Hence, on day K+n, day n's fruits are still good.

    scanf("%d", &K);

    for (int i=0; i<N; i++) { // i is day number from 0 to N-1;
        scanf("%d", &G[i]); // input number of fruits each day.

    }

    for (int i=0; i<N; i++) {
        scanf("%d", &E[i]); // number of fruits you can eat.
        Et += E[i];
    }

    // All done with the input, go through the output!

    // OUTPUT SECTION

    // Algorithm is to eat the fruits that expire first.
    int F=0; // max fruits
    int C=0; //day number can eat which starts at 0, notably i-K;

    // On day i=2, day 0's fruits expire when K=1.
    // On day i=3, day 0's fruits expire when K=2.
    // On day i, day i-K-1's fruits expire.
    // input order is
    // N K
    // Array G
    // Array E

    // Hence, increment to 1, when K=1, if C < 1, when i > 1.
    // increment to 2 if C < 2, when K=1, if C < 2, when i > 2.
    // increment C by 1 when day 0's expired, when K=1 and i=K+1.
    int d=0; //day number
    int status=0;
    while (Et>0) { // Et is remaining
        if(C<d-K && d>C+K) {

            printf("Day %d's fruits expired.\n", C);// commentout
            Et-=G[C];
            if (C+1<N) C++;
            printf("Start eating day %d's fruits\n", C); //comment out
        }




        if(G[C]<=E[d]) { // eat all if the fruits left is lesser than what you can eat.
            printf("Ate %d (all) of Day %d's fruit(s)\n", G[C], C); //commentout
            E[d]-=G[C];
            Et-=G[C];
            F+=G[C];
            G[C]=0;
            printf("Day %d's fruits are finished.", C); //commentout
            if (C+1<N) {
                C++;
                printf("Start eating day %d's fruits\n", C); //comment out
            } else {
                printf("\n");

                break;
            }
            if (E[d]==0) d++;



        }
        if (Et==0) {
        printf("No more fruits!\n"); //commentout
        break;
        }

        if(G[C]>E[d]) { // eat just E[d]=2 remaining fruits for the day.
            printf("Ate %d (remaining/next) of Day %d's fruit(s)\n", E[d], C); //commentout
            G[C]-=E[d];
            Et-=E[d];
            F+=E[d];
            E[d]=0;

            if (G[C]==0) {
                printf("Day %d's fruits are finished.", C); //commentout
                if (C+1<N) {
                    C++;
                    printf("Start eating day %d's fruits\n", C); //comment out

                }    else {
                    printf("\n");

                    break;
                }


            }
            d++;

        }
        if (Et==0) {
            printf("No more fruits!\n"); //commentout
            break;
        }


    }
    printf("%d", F);
}