Submission

Score: 100

User: Frankenstein

Problemset: B.Shuffle

Language: cpp

Time: 0.063 second

Submitted On: 2026-04-12 16:03:12

#include <cstdio>
#include <unistd.h>

static char buf[1 << 22];
static int bufPos, bufLen;

static inline int gc() {
    if (bufPos == bufLen) {
        bufLen = (int)read(0, buf, sizeof(buf));
        bufPos = 0;
        if (bufLen <= 0) return -1;
    }
    return buf[bufPos++];
}

static inline int readInt() {
    int c, x = 0;
    do { c = gc(); } while (c <= ' ' && c != -1);
    for (; c > ' '; c = gc()) x = x * 10 + c - '0';
    return x;
}

static char obuf[1 << 20];
static int oLen;
static inline void flush() { write(1, obuf, oLen); oLen = 0; }
static inline void writeStr(const char* s, int n) {
    for (int i = 0; i < n; i++) obuf[oLen++] = s[i];
}

int main() {
    int T = readInt();
    while (T--) {
        int M = readInt();
        // skip whitespace, then read M chars directly
        int c;
        do { c = gc(); } while (c <= ' ' && c != -1);

        int xr = 0;
        int parity = 0;          // 0 = waiting for first block of pair, 1 = waiting for second
        int gap = 0;             // empties counted since first block of current pair
        int processed = 1;       // already consumed one char (`c`)

        // process the first char we already read
        if (c == '_') {
            if (parity == 1) gap++;
        } else {
            if (parity == 0) { parity = 1; gap = 0; }
            else { xr ^= (gap & 1); parity = 0; }
        }

        while (processed < M) {
            c = gc();
            if (c == '_') {
                if (parity == 1) gap++;
            } else if (c != -1 && c > ' ') {
                if (parity == 0) { parity = 1; gap = 0; }
                else { xr ^= (gap & 1); parity = 0; }
            } else continue;
            processed++;
        }

        if (xr) writeStr("YES\n", 4);
        else    writeStr("NO\n", 3);
    }
    flush();
    return 0;
}